Within the Space of a Heartbeat

The Mark of the Time Traveler #2

by Elise Helliwell

In the sequel to Within the Space of a Second,  old lovers and new enemies confront deadly secrets at a time-travel academy where no one can be trusted – for fans of slow-burn romance, gripping magical realism and shocking plot twists.

It’s been two years since Ella said goodbye to Parker, the charismatic time traveler who rewrote her past and stole her heart. Determined to reunite with him, she enters Neurovida, a secret institution that will train her to time travel – even if, according to Ella’s haunting dreams, Neurovida is also the place she’ll die.

At the academy, Ella and the other recruits face brutal competition and grueling time-travel tests designed to dwindle their numbers. Ella will do anything to maintain her place, but when a near-fatal blow forces her into a dangerous bargain with fellow recruit Matthews, she’s pulled closer to the very person she fears most.

Haunted by a past built on lies and desperate to reclaim her future, Ella must embrace the power she’s spent her life fearing… even if it means relying on the one person who could destroy her. 

400 pages, Kindle Edition

Expected publication December 1, 2026

About the author

Elise resides on the Sunshine Coast, Queensland, with her husband and two young girls. An avid romance reader, Elise writes contemporary and sci-fi/fantasy romance, juggling themes of love, anticipation and emotional angst.

Part time scientist/radiographer and full time hopeless romantic, Elise’s writing combines her love of science and the romance genre to produce suspenseful, swoon-worthy love stories that will keep the reader falling until the very last page.

When Elise isn’t parenting or writing, she’s either in her head watching characters and storylines come to life, or curled up at home with a glass of wine in hand, reading romantasy or contemporary romance.

Connect with Elise:
Instagram/TikTok: @elisehelliwellauthor
Facebook: Elise Helliwell Author

Reviews

[Ellyse Moir · Rating 5 out of 5]

Is it too early to call this my favourite series ever?? I don’t think I have the words to properly convey how much The Mark of the Time Traveler both emotionally devastates me and injects me with electric joy all at once. I was juggling three other books when I picked this up, and had to abandon all of them until I finished WTSOAH because I. Could. Not. Put. It . Down. There is so much to love, from the romance to the drama and everything in between; this cast of characters owns my heart. I could devour ten more of Elise Helliwell’s time travel books and it wouldn’t be enough. I ADORE THIS SERIES!!

Spoilers ahead 💖

As a sci-fi/fantasy girly, seeing the magical realism become more front and centre to the plot in this one was DELICIOUS!! We had trials, tension, rivalries, and high stakes. The way our characters were a part of (what we believe to be) the first class at Neurovida gave me such X-Men: First Class vibes, and I loved getting to learn all the cool time travel lore alongside our characters. I’ve never seen a time travel plot written this way before; it felt so original. Learning about the different kinds of travel, and the unique abilities people possess, was thrilling. The struggles our characters feel while trying to master their powers make them so believable and three-dimensional, and I was invested in every single one of their journeys (well, maybe not Gloss or Slate, but that’s valid). I know there’s some shady shit going down at that school (looking at you, Nickol) but I would seriously drop everything to go and train there. I got no self-preservation instincts and would probably flunk out before the first test, but hey, I’d give it a red-hot go if it meant potentially becoming a time-travelling badass with a soulmate.

If I could time travel, I’d go back into the past and slap my former self. She was so sure she’d die on her Liam hill, but WTSOAH did the impossible and made me switch up to team Silas?? I NEVER THOUGHT IT WAS POSSIBLE!! And yet the level of yearning and soulmatism between Matthews and Flame is undeniable. Every twist, every reveal, made me fall for them so much harder, and by the end, I was a wreck, because we as the reader know what’s coming, and it’s going to be so heartbreaking. The transition between Ella’s relationship with Parker and Matthews was done so well, too. It didn’t feel rushed or plot-devicey; we understood every decision Flame made and her every reaction was justified. Parker was such a mess in the beginning!! And when she found out he was sleeping with Gloss, it was so devastating. She literally came to the academy to be with him, only to have her heart broken. I know he had his own issues to deal with, and she had unrealistic expectations, but having the contrast of Parker’s poor choices and Matthews unflinching care made it easier to open up to the idea of a new main love interest for Ella.

Where book one mostly rotated between Rose and Ella’s POVs, we get a new main POV in book two: Matthews. We discover who he really is, his history, his motivations, and his unwavering commitment to keeping Ella safe. It hurts so much to fall in love with Matthews, and then also see his future self in unbelievable pain because not only has he lost his Flame, but he is being tortured by fellow Alphas. I NEED TO GIVE THAT MAN A HUG!! That scene where Flame travels into Silas’s memory to the moment she stopped time before her death?? Pain. Nothing but pain. And it makes you look at Silas’s actions in book one SO differently. He must have been in agony the entire time. A HUG!! JUST ONE!! I also love how different Ella is in this book. We see a much softer side of her in the first book, then once she becomes Flame, we get to watch her confidence grow and an impressive determination take root. She trains with Matthews and starts believing in herself, getting stronger all the time while still staying in touch with her emotions. I love a protagonist who is both badass and unashamedly feminine. Flame is further proof women can wear dresses and still take down bad guys!

I wasn’t prepared for how hard the found family element would hit me. We had a taste of it in book one, when we find out about the Alphas, but seeing their friendship come to fruition in this book and culminate in that scene at the end by the lake made me BAWL. Each character had a distinct personality, coming in with different backgrounds and varying traumas. Seeing someone like Bandit, who is relatively bubbly and confident, become friends with someone like Rose, who is prickly and standoffish, was a treat. It was strange seeing a more rich-party-boy version of Parker compared to the compassionate Liam we came to know, but I even learnt to appreciate his cocky charm. I may still be a little suspicious of Axis and his visions, but even he has my affection. They all learn to trust one another and form an unbreakable bond, finding strength as a little time-travelling family. If Flame, Matthews, Parker, Rose, Bandit, and Axis don’t all make it out of this series alive, I’m gonna sob. Leave my Kairos babies alone, Neurovida!!

I also have to mention the humour in WTSOAH. I wouldn’t call it a comedy, but there are some scenes that had me CACKLING. I know their final test was very serious with very real stakes, but that scene where Matthews was in a room with over twenty versions of himself made me wheeze. The way they tried to tackle him to stop him from leaving conjured such a funny mental image. And the Rose/Parker dynamic was hilarious, too. Every time she called him Jimmy, or he made a comment about how delightful she was, I laughed. And that time Flame landed a proper punch to Matthews face? Hilarious. For a story that carries such emotional weight, having these witty moments to lighten the mood really made for a memorable experience.

I am SO impressed by this book on a craft level as well. Not only is the prose lyrical, the dialogue funny, and the plot riveting, but the foreshadowing with all the time travel is outstanding. The attention to detail is off the charts; I’m astounded by how perfectly Helliwell keeps track of all the timelines. There are easter eggs EVERYWHERE in both books, and they’re planted so impeccably that when you realise what happened, you can’t help but be in awe. I simply NEED to go and reread book one, because I know there will be new things I see with the knowledge I’ve gained. Honestly, no series has made me theorise as much as this one. There are so many possibilities, so many pathways the story could take. Who is Fan? Is it really her mother? (my crackpot theory is that it’s a version of Future Silas, but time will tell…) Secrets are everywhere and since Neurovida isn’t what it claims to be, I can already feel the chaos coming in the next installment.

I literally have no criticisms for this book. It’s flawless. Amazing. Showstopping. Spectacular. There was no second book syndrome; if anything, the sequel was even BETTER, building on the world we dipped our toes into in the last book and introducing us to both new and new-yet-old characters. Everyone needs to stop what they’re doing and pick up this series NOW, it’s that serious. Let the current carry you…to your local bookstore, so you can pick up a copy. Infinite stars!! Romance on an epic scale, time travel as you’ve never seen it before, and secrets that will change the course of history. Can I travel into the future and read book three now?

[Awesome_Ames · Rating 5 out of 5]

Buckle up book friends, because there is no second book syndrome happening here! In fact, this is actually BETTER than book 1!

“I love you … Every version, in every timeline. Past, present and future. I love you.”

I did not expect to have my understandings and feelings about this world turned upside down, let alone be super happy about it and excited for the next instalment. Absolute magic!

I could not put this book down. The bath water went cold, everybody had dinner late. This is a cannot stop at the end of the chapter book - consider yourself warned!

I want to note, that Elise’s writing is incredibly immersive. It’s binge-worthy. Time travel isn’t the simplest topic to write about either, there are so many rules to consider and keep track of. Then add in the magical realism throughout the book, and the storyline alone, which means there’s a lot going on, and yet at no time was I confused or lost. The writing is exceptional.

I was thrown at first by the name change - who is Matthews?! - and it is all explained before you dive back in with the author’s note at the beginning; but the way it actually worked to enhance the storyline is so clever!

The character growth is masterfully done. We’re encouraged to engage with abstract concepts in ways I hadn’t considered before. Do you wait for the person someone is supposed to become? How much trust is too much trust? Where’s the line between fate and free will? How do you bear witness to the development of someone you can trust, including the consideration of at what point can you trust yourself, and knowing when you’re there?

Every decision made by Mariella is understandable and so well justified. We get reasoning. As shocking as the twists are, they make sense, and I woudn’t have wanted it any other way. Mariella/Flame is such an inspiring character to read about, and I am thoroughly enjoying her character growth and relationships journey. Elise carefully balanced the line of emotional investment without utter emotional devastation, in the right places.

The attention to detail is superb. When I finished, I immediately wanted to go back and reread book 1 to look at it with new insight, and see if I missed any Easter eggs. There are so many timelines, events, important minute details, and Elise is the puppet master. I can’t imagine the planning board for this series!

That cliffhanger has me speechless. Whhhaaaatttt?!!?!!! I am desperate for book 3!

Favourite moments:
💞 Trials - brutal!
💞 Tension and yearning (he falls first and OMG hot!)
💞 Rivalries
💞 Flashback chapters
💞 X-Men vibes
💞 Multi-POV’s (Matthews and Thomas in particular)
💞 Soul mates - what do you mean soul mates!!!

[Stephanie Grosse · Rating 5 out of 5]

I finished the ARC of Within the Space of a Heartbeat by Elise Helliwell moments ago, and I already know it is going down as one of my favourite reads of the year.

This sequel to Within the Space of a Second was completely captivating. Elise has an incredible ability to tackle complex and incredibly heavy subjects, including abuse and mourning, with such care. Nothing ever feels forced or in your face, yet the emotional impact is still incredibly powerful. I was completely invested in these characters and their stories from beginning to end.

And if you go into this book thinking you know what is going to happen because you read the first book, prepare to have everything you think you know turned upside down. I was constantly questioning who could be trusted, what was real, and where the story was going to take me. Elise kept me guessing right until the very end.

I also have to say, I NEED more Neurovida. I know this was originally a two-book deal, but Elise, I am begging you: please, please give us another book! I am absolutely not ready to leave this world behind.

Captivating, emotional, clever and completely unputdownable. An easy five stars from me.

Thanks again to Elise, Simon & Schuster and Atria Books for the physical ARC 💕

[Chloe’s Book Corner · Rating 5 out of 5]

✨Within the Space of Heartbeat✨
5⭐️📖

The book truly was a masterpiece.
The yearning oh my goodness 🤭😫🥰

It was bloody incredible I loved every single minute of it. 5 stars 10/10 I think I may love it more than book 1 wow I’m in totally shock right now.

Oh my lord, this was so incredible, from start to finish I couldn’t get enough of it.
I was obsessed with book 1 but honestly I think book 2 top it. It is everything you could want in a fantasy book and more.

This no fantasy book like it. It has every single genre and trope that I love.

The romance and fantasy element of course but the mystery element as well that keeps you in suspense. Also enemies to lovers.
Obsessed with the world and the characters.

The flashbacks chapters were so interesting and added so much to the plot and I was obsessed with them.

The ENDING 😳😱 omg the ending it book 1 was incredible but the ending in book 2 was insane.

It was surprise plot twist after plot twist and I loved it 🥰

I can’t recommend this book enough, I don’t want to say too much because I don’t want to spoil it but it’s definitely worth adding to your TBR.

Within the Space of Heartbeat
Out 1st December!! 💜💚📖

[Pawsandpagesonthecoast · Rating 5 out of 5]

Before I start, some characters have different names across the different timelines, so I’m only going to use one set of names to avoid any confusion.

After loving Within the Space of a Second, I couldn’t wait for Book 2. I was so excited to be able to continue Mariella’s journey into Neurovida and, of course, see where her love story with Parker would take us.

Book two was everything I hoped it would be and so much more.

I’m trying really hard to keep this spoiler free because it isn’t out in stores until December, and there is SO much in this book that you really need to experience for yourself.

Neurovida gave me everything I wanted. The trials, the fights, the love story, the twists. But absolutely none of it happened in the way I expected.

Elise completely blew me away with the detailed character stories and one particular characters background woven throughout the entire book. It added so much depth and understanding to a story I already thought I knew.

Then there’s a surprise character who is featured throughout the story and ended up bringing me to tears. When you know, you know.

This story went in a direction I never could have dreamt up, and it was honestly so much better than anything I could have imagined going into it.

We still have Parker, Rose and Mariella, who I already loved from book one.

And then there’s Matthews.

Somehow, I now adore Matthews.

I genuinely NEVER thought I’d be saying those words, but I understand him on such a different level now. The character development is so rich that it completely changed my perspective on him.

There were so many gasp moments throughout this book, but those last few short chapters had me absolutely flying through the pages. I just needed more and more.

And I have to include one of my favourite quotes because this was just magnificent:

“Following him feels like the oldest song, the notes woven through my soul. Familiar. Certain. And time and time again, I fight against it. Head versus heart.”

And that ending…

I am LONGING for the next book.

An easy 5 stars. Brilliant.

[Emma Eva Lanaway · Rating 5 out of 5]

✨💘⏳𝓦𝓲𝓽𝓱𝓲𝓷 𝓣𝓱𝓮 𝓢𝓹𝓪𝓬𝓮 𝓞𝓯 𝓪 𝓗𝓮𝓪𝓻𝓽𝓫𝓮𝓪𝓽 ⏳💘✨

⭐️ ♾️
🌶️ 2

Beyond grateful for an ARC of this book… this has got to be one of the best books I’ve read this year… I cannot wait for this to be released in December…

I can’t really talk about anyone other than Mariella without spoiling it… but what you think you might know from WTSOAS… prepare to be shocked! This series has been so cleverly written, the way Flames past, present and future self are all changing and growing.

I need book 3 more than I need air… I have so many questions… FEN?! DRIFT?! EVELYN?! Axis and Bandit?! Honestly anything can happen and I have absolutely no idea 🤷‍♀️ which I LOVE!!

I will be rereading in December when this masterpiece drops, and I will eagerly await anyone else who reads it! I need discussions! 🤣⏳🥰✨💖

[Paige · Rating 5 out of 5]

First up thank you to Elise for sending me a copy I won for being a part of your street team. Love you long time 💗🫶🏻

So book 1 I really enjoyed and let's just say I was expecting some things from this book and well I was sorely wrong and very mistaken. Elise has created a story with time travel that is weaved with different timelines and how she keeps up with it? I don't know, but she nails it! 👏🏻👏🏻

Mariella is different in this book, she's stronger and finally FINALLY stops letting people tell her about her life. Also thankfully she stops listening to Liam 😏

Silas is literally the best and it makes you understand him from book 1 soooooooo much more. I knew absolutely knew something was with him in book 1 and it's soooooooo now obvious when you reflect on book 1.

Anyway the way book 2 is written made me read 310 pages in one sitting cause I couldn't stop reading. I loved it. And everyone needs to read this book 📖

[Mandy Enchantedbookduo · Rating 5 out of 5]

Rating
5 💎
1 🌶️

Summary
I was so excited to jump back into this world and finally see how Mariella’s time at the academy would unfold. Parker turned out to be nothing like I expected, while Matthews is quickly becoming a favourite, even though I’m pretty sure I’m not supposed to like him! The tension and slow build between these two had me completely invested, and I was rooting for them the entire time. I was so hooked I stayed up until 1am because I couldn’t put it down. The deeper mysteries and character backstories only made it better. I absolutely loved every page of this one!

While Reading Thoughts
💜I was so excited to jump back into this world, desperate to know how Mariella’s time in the academy goes
💜Well Parker is nothing like I thought he was going to be
💜Starting to really like Matthews even know I think we not supposed to
💜Now I am rooting for these 2 soo hard, the tension and building of their relationship is just fantastic
💜I stayed up till 1am as I could not out it down
💜Loved the opening up of further mysteries and uncovering more of the backstories on the characters
💜This was sooo amazing, loved every page.

Words that linger
💬This is wrong isn’t it? So why do I need his hands on me like I need oxygen?
💬I’m in love with you, Mariella. I have been for a long time. But now? You consume me.
💬Once you step foot in Neurovida, you can never leave. You die no matter what.
💬In every timeline it’s you…Whether you enter the past or meet me here. It’s always you.

Tropes
⏳Enemies to lovers
⏳Touch her and die
⏳He falls first
⏳Magical realism
⏳Soul mates

Thank you Elise, Simon & Schuster Aust & Atria books for the early physical copy.

HELL YEAH You absolutely smashed this out of the park!!!

[Shae Mann · Rating 5 out of 5]

The first book was amazing… but this one was SO much better.

And I need to point out that I am not normally a second-book girl. If I’m reading a trilogy, I’ll obviously keep going, but the second book is usually the one I’m just reading to get to the next part. That was absolutely not the case here. I am fully obsessed.

The way Elise Helliwell handled the time travel in this one was honestly so clever. Having the past and present versions of characters use different names made it SO much easier to follow what was happening. I normally struggle so much with time-travel stories because my brain starts doing backflips trying to keep track of everyone, but I understood everything. I never felt lost, and I actually found myself really enjoying trying to piece everything together.

The world-building was also on another level compared to the first book. The first book was very dialogue-heavy, whereas this one gave me so much more of the world, the history and everything happening around the characters. I felt like I got so much more out of the story this time around.

And some of these characters made me SO angry. Like genuinely angry. 😂 There were moments where I was sitting there thinking, how are you doing this right now?! But I was completely invested, which is exactly what I want.

I’ve also been reading A LOT of romantasy lately, so this series has been such a fun change of pace. It feels so different from what I’ve been picking up recently, and I’ve absolutely loved getting into something that made me think a little more while still being ridiculously entertaining.

And then the ending.

I am deceased.

This book isn’t even officially out yet and I’m already sitting here wondering how long I have to wait for book three because I genuinely do not know how I’m supposed to move on with my life after that???

[Stacey (sassysreadingnook) · Rating 5 out of 5]

What a fantastic sequel! I was hooked by the mix of time travel, magic, mystery and romance. Mariella’s determination to find her way back to Parker had me invested from the start, but Neurovida turned out to be anything but what she expected.

The academy setting brought plenty of tension, with brutal challenges, dangerous competition, secrets and twists that kept me guessing. I loved the darker atmosphere and the constant feeling that nobody could really be trusted. The complicated dynamics between Mariella and Matthews added another layer to the story, especially with all the uncertainty and tension between them.

There’s so much happening beneath the surface, and just when you think you have things figured out, another secret or unexpected twist comes along. I loved watching Mariella face her fears, discover her strength and fight for the future she wants.

A brilliant combination of suspense, slow-burn romance and jaw-dropping twists. I was completely invested in the characters and their journey, and I couldn't put this one down. If you love magical academies, time travel, dangerous secrets and romance with plenty of tension, this is definitely one to add to your TBR!

[Read.Recap.Repeat · Rating 5 out of 5]

⏳🔥 “Once you set foot in Neurovida, you can never leave. You die no matter what.” 🔥⏳

Time travel, dangerous secrets, complicated connections and a story that will leave you questioning EVERYTHING! 🤯

Mariella enters Neurovida knowing that failure means death, but as she uncovers secrets about the past, the people around her and the mysterious Matthews, she begins to realise that nothing is as it seems. Who can she trust when everyone has something to hide? 👀

This book had me second guessing everything, and THAT CLIFFHANGER?! I NEED the next instalment NOW! 😭🔥

Tropes You’ll Love 🥰
💕 Soul Mates
⏳ Time Travel
❤️‍🔥 Slow Burn
🖤 Enemies to lovers
👯 Dual POV
☠️ Touch her & dle
🥰 He falls first
🌀 Magical Realism

💭 I loved watching Mariella discover her own strength and learn to trust her instincts when nothing around her felt certain. The twists kept me guessing, the emotional push and pull had me invested, and that ending has me desperate for more!

A huge thank you to Elise Helliwell for providing me with a copy of this ARC in exchange for an honest review. 🖤📚

[Jessica Noela · Rating 5 out of 5]

The perfect follow up to book one and the perfect set up for book three!!!

Was so good to be back hanging with the time travellers and getting some extremely helpful background information! (It really makes you go ooooo that makes sense)

I loved every second of reading this book it was truly amazing and something Elise should be proud of.

I especially loved the flashback chapters and how everything was building and leading to one moment that left you on the edge of your seat wanting more, with an ending that has you going WTF! Did not see that coming!!

This amazing work of art (literally have you seen the sprayed edges it’s coming out with???) is out in December so make sure your ready to not sleep and devour this epic book!

Thank you so much to the author and publisher for this early copy!!

[August · Rating 5 out of 5]

Oh my gosh what a twisty read. Set in an academy to time travellers full of secrets and different timelines this had me so addicted. Time travel always does something to my brain where if you think about it too much, I get so completely lost, and I admit to spending parts of this thinking "what's going on?" but in the best possible way. The romance was a super slow burn, with lots of will-they-won’t-they. I wasn’t entirely convinced by it at first, but the ending absolutely made it worth the wait.

Thank you to Netgalley and Simon & Schuster (Australia) for this ARC.

[Meredith · Rating 5 out of 5]

Wow. What a ride. Anyone that knows me, knows I must have someone to debrief with as I’m reading the chapters. Being that I was kindly gifted an ARC, my wild theories landed in my friend Elise’s inbox (the fabulous author).

I can confirm. My theories were wild. Unhinged. Some of them were fairly embarrassing in hindsight. But I just loved this book!

It’s difficult to review thoroughly without giving away any spoilers. But there was a return of some favourite characters, and the most heartwarming connections made. I loved all of the timelines and filling in some more history of our favourites.

If you loved The Time Travellers Wife, and an academia setting, this would be a fantastic pick for you!

[kaitlyns_library · Rating 5 out of 5]

I love the vibes of this! I read another review that says this series gives off X-Men vibes and I totally see it! I love every twist and reveal that was being fed to me in this book. Also I love a good trial and fight too!

[Isabelle Gorton · Rating 5 out of 5]

*Received an Arc copy from the author for an honest review.

Book 1 had me hooked on Mariella and Parker’s story, but I knew Silas HAD to have a bigger part of the story, and I’m so glad that he did.

Within The Space OF A Heartbeat gave the audience a full, in depth breakdown of Matthews, aka Silas. And let’s just say, Parker who?!

I absolutely loved that Flame didn’t stick to what she had been told and made her own path. Her strength to seperate herself from her expected future, and carve her own future is a showcase of how every woman should choose herself first.

Elise’s ability to transform her characters in this novel was extraordinary. She was able to show that Flame is not her future, she has the strength to pick her own path. Further, she showed that you don’t have to be the one to help someone out of their darkness if it affects you. By allowing Flame to seperate herself future relationship with Parker and break the pattern, she proved to herself that she was worthy.

Matthews character development was phenomenal. I loved the glimpses into his past and experiences, and finally understanding his relationship with Flame. Their connection is one for the ages.

I cannot wait to see where Elise takes book 3

[Hayley Sutherland · Rating 5 out of 5]

I loved this book so much. It kept me totally engaged from the very first page.
I loved the school setting, the learning and competition against each other was so good.
I loved the bouncing between pov’s and times. It kept me wanting more and my brain trying to piece everything together but not confusing me at the same time.
The ending… I need more!

[the_bookishbee_ · Rating 4.5 out of 5]

• Review of advance copy received from publisher •

Another sequel that is even better than the first!! A twisty, time-bending ride that kept me guessing the entire time.
 
I loved being back in the world of Neurovida, continuing to explore endless secrets, cover ups and drama! Although everything is different…timelines are rewriting themselves, changing and morphing into a new, unknown future, will everyone survive?!?
 
First up I have to say…time travel is explored so beautifully in this story. It evolves naturally, it’s not information overload and the different timelines, perspectives and revelations constantly give you pause to think and really ponder each little revelation. Just when I thought I had things figured out, there was another twist that came barrelling along to prove I absolutely knew NOTHING 🤣
 
At the centre of this story is the new Neurovida recruits navigating their training and of course, it’s anything but simple. We are shown a raw, gruelling and emotionally challenging journey as recruits push themselves to the limit to discover and expand their abilities, in the hopes of earning their place as a permanent time traveller.
 
The characters on this journey are also confusingly different from what we have been led to believe they will be like. Has the timeline been altered or is there something more sinister happening? I was giving so many characters the side-eye, just waiting for the double cross to drop! While I will not go into too much detail to avoid spoilers, Mariella is still a fave. She’s stronger and more determined than ever and refuses to sit back and accept the increasingly complicated situations she’s finding herself in… she’s now pushing back and fighting for what she wants, we love to see it! I love to see it 🥰 Especially with Parker and Matthews! These two! We get to experience the slowest of slow burns, yearning and one hell of an emotional rollercoaster. Strap in, is all I can say!
 
All the relationships between the characters are addictive and we get complex dynamics and tension threaded through each and every interaction. It’s in these interactions that we start to get the secrets of their pasts revealed and then watch and wait to see how this shapes and influences the present. Because of these twists and turns I was kept guessing right til the end… and of course, there was an INSANE cliff hanger that definitely deserves a few choice words! In this setting I will stick with OMG 😱
 
Within the Space of a Heartbeat is an incredible mix of fantasy, romance, mystery and time travel and an exceptional continuation of The Mark of the Time Traveller series. So now I’m expected to patiently wait for the next instalment. Absolutely not… I need to know what happens like, yesterday.
 
Thank you so much to the publisher and author for an ARC in exchange for an honest review and renewing my love of time travel stories <3

[Kelsbookreads · Rating 5 out of 5]

⭐️ what I arc read this week ⭐️

I found myself inhaling Within the Space of a Heartbeat, book two in The Mark of the Time Traveler series. And when I say inhale...I read it over 12 hours.

Elise has written a riveting and exciting sequel that not only has you on the edge of your seat, but has your heart invested to such a degree that you'll be yelling at the characters for the decisions they make and the actions they take (or don't). It's breathtaking, swoonworthy and such an intriguing spin on time travelling lore.

Mariella, or Flame, has infiltrated Neurovida (a secret time-travelling academy) ready to change her devastating future and to be reunited with Parker, well, the younger version of the man she fell for. Trouble is, he has no concept of their future and is, to be frank, not the person she believed he was, but she holds steady, knowing what will happen if she stays true to her mission.

But what she wasn't expecting was Matthews younger version to be there. The man who betrayed her, who used her... who ends her life years in the future. Though as the weeks go by, the version she meets in Neurovida is nothing like the secretive and callous man she once thought she knew. This Matthews ensures she's prepared for the fight, that she's looking after herself and Mariella suddenly finds herself unable to trust her own judgement.

This book is so much bigger than the romance though. The mystery surrounding their pasts and their futures is tantalising,  Elise giving the reader just enough to get hooked. And hooked I am.

If you adore:

- slow burn
- he falls first
- touch her and die
- soul mates
- enemies to lovers
- dual POV
- magical realism
- incredible worldbuilding
- secrets
- an ending that requires the next book stat

Then add this to your tbr now! I read this prior to official release.

[Liisa · Rating 5 out of 5]

⭐️⭐️⭐️⭐️⭐️ 5 GLORIOUS STARS!

I ADDDDDOOOOOORED THIS.

I didn't think I could love anything more than Within the Space of a Second, but apparently Elise Helliwell woke up and chose violence with book two. And I am HERE FOR IT.

I'm currently on holiday overseas. Supposed to be sightseeing, exploring and generally enjoying myself.

Instead, I've been reading this like a feral goblin into the wee hours because I simply could not put it down.
And honestly? No regrets.

Neurovida gave me EVERYTHING I wanted. Brutal time-travel trials, complicated relationships, enemies-to-lovers tension, delicious slow-burn romance and THE YEARNING. 🤭 But absolutely none of it unfolded the way I expected.

With new POVs, fascinating flashbacks and twist after glorious twist, I spent approximately three-quarters of this book questioning everything I thought I knew and everyone I thought I could trust.

Helliwell handles the increasingly intricate time travel so cleverly, particularly by giving past and present versions of characters different names. It makes the timelines surprisingly easy to follow without sacrificing any of the suspense.

I'm trying desperately to keep this spoiler-free because there's SO MUCH you need to experience for yourself.

But THE ENDING.
I AM DECEASED. 😳

The book isn't even officially out yet, and I'm already wondering how long I have to wait for book three. HOW AM I SUPPOSED TO MOVE ON?!

An absolutely glorious rollercoaster of a sequel. I genuinely think I loved it even more than book one.

Out 1 December 2026.

Thank you to Elise Helliwell, NetGalley and Simon & Schuster Australia for the eARC.

[Anita · Rating 5 out of 5]

Advanced reader copy review of Within the Space of a Heartbeat by Elise Helliwell
⭐⭐⭐⭐⭐ - I really, really loved this!
🔥🔥🔥 - explicit, 1-2 scenes, vanilla.

I had a feeling that I would love this book. The second book in the Mark of the Time Traveller series did not disappoint. I enjoyed this so much more than I expected!

It did take me a few chapters to wrap my head around the different names the characters were using throughout this book, compared to the first book. However, it's been close to a year since I read the first book, and I made no effort to remind myself of what happened - oops.

The writing and flow of the story was excellent. I enjoyed the tests and the lessons that the Neurovida recruits went through, as well as the build of their relationships with each other.

I did not anticipate that Matthews/Silas would end up being Mariella's soulmate, but I am not mad about it. The slow reveal of more detail about his past and just who he is was incredible. I have no notes.

I am so intrigued by the change in everyone's memories, including the differences between Mariella's present and what Rose and Parker told her would come to be in the first book.

I'm keen as mustard for a third book in this series. Fingers crossed!

Disclaimer: I read an advanced copy of this novel. I was not incentivised to read or review. Thank you to Elise Helliwell, Atria, and Netgalley for the ARC.

[Tiffany · Rating 5 out of 5]

This series has turned me into a giddy school girl heavily crushing on the boy she likes… but the book version 😂.

Within the Space of a Heartbeat starts exactly where book one ends. Mariella finally enters Nurovida, ready to learn to time travel and still hopeful that she can change her future, because she has seen for herself that time can be messed with and that ‘fate can change’ ✨⏳.

On her arrival, Mariella meets the younger version of Parker and is smitten all over again. But, of course, then there’s Matthews. He absolutely terrifies Mariella, but she is also so drawn to him. And the secrets he is hiding? Honestly, I didn’t see them coming, but they were SO bloody good 🤩.

Of course, this wouldn’t be the same series without all the twists and turns, breadcrumbs and cliffhangers we came to expect after book one, and oh, this book delivered them so well 🧩🤔.

Can events and timelines be changed so much that what Mariella is waiting for and expecting to happen just doesn’t come to fruition? And can this version of her timeline actually be the version that was always meant to happen? 💖💖

I received a free physical Advanced Reader Copy of this book from the author, all opinions and comments are my own. I truly loved this book.

[Kat J · Rating 5 out of 5]

This Was So Good!! Elise weaves an intoxicating narrative that draws you in while slowly unraveling secret after secret and keeps you guessing about each character and what happens next. This is a sloooooow burn and the longing! Sigh….the longing just hits you.

If you love time travel, slow burn, desperate longing, and a puzzle that is slowly revealed - this is for you although I strongly suggest you read book 1 - Within the Space of a Second for some of the context.

Book 2 commences right where book 1 left off and the way we follow Flame through the process and training at Neurovida is just so gripping the way it’s been written and keeps you absolutely absorbed into the story and honestly, the more you learn about each character, the more you wonder if what you thought you knew was right. The heartbreaking backstories! Who is telling the truth, who is the enemy and who can you trust? You think you know what is going to happen because of book 1……you don’t! And then there is the ending!!!!! OMG!!!! I can’t wait for Book 3!

[Kimmii Skye · Rating 4.5 out of 5]

I was lucky enough to receive an ARC of Within the Space of a Heartbeat.

I finished book 1, Within the Space of a Second late afternoon on a Sunday and immediately picked up book 2 and literally devoured it before 10PM that same night.

I really enjoyed the time travelling in this book, it wasn’t too difficult to follow, whilst I would have liked to maybe have more POVs from some characters - by the end of the book I understand the why?!

I am still sitting here wondering if I’ve been bamboozled and whether Book 3 will continue bamboozling me, turn everything I thought I knew upside down or leave me shocked, and gleefully happy at the turn of events.

The yearning and slow burn in this book is nice, but I think the self worth message is even better.

4.5 ⭐️⭐️⭐️⭐️⭐️
1-2 🌶️🌶️ (depending on whether you judge your chilli on explicitness or # of pages).

I am very glad I read this series!

[TheSarahChapters · Rating 5 out of 5]

⭐⭐⭐⭐⭐
Within the Space of a Heartbeat by Elsie Helliwell
Thankyou so much to the Queen herself for gifting me an ARC of book 2 in the mark of the time traveller series!

What an absolutely beautiful and captivating read! Within the Space of a Heartbeat drew me in from the very beginning, starting exactly where book 1 ended. Elsie has created a story filled with emotion, heart and wonderfully engaging characters that continuously pop up in my thoughts from day to day.

I loved the way the story unfolded, so many unexpected twists and the emotional depth that made it so easy to become invested in the characters and there were moments that genuinely made me laugh, ache and hope alongside the characters.

Absolutely adored everything about this book! .A well-deserved 5 stars from me! ⭐⭐⭐⭐⭐

[Clare · Rating 4 out of 5]

🩷 Book Review 🩷
📚 Within the Space of a Heartbeat
✒️ Elise Helliwell
💫💫💫💫

Thank you to Atria Books for an eARC in exchange for an honest review.

I honestly did not think that this series could get better, but somehow it has! Elise has this amazing ability to weave intricate worlds and characters that have you hooked.

I have read previous time travel books, and they often have issues with timing or explanations of worlds but Elise never once struggled. The past and the present collide, but we see the same characters with different names!

I don't want to spoil anything, but damn that ending hurt me. It was a twist I never saw coming and secrets are spilled.

I cannot wait for book 3!

[Kirsten · Rating 4 out of 5]

A gripping romantasy time travel story.
Within a Space of a Heartbeat is the to Within the Space of Second. I would definitely recommend reading book one first to get a feel for the world building and the characters back story. Set in Neurovida, a time travel academy. I enjoyed the dark academia setting, learning about the different types of time travels and seeing the characters learn to use their different powers. I loved the camaraderie of the found family but also the tension and rivalries between the characters.

The story unfolds over multiple points of views points of views of as well as flashbacks. I enjoyed seeing Ella gain power and inner strength as she worked out who to trust. I was surprised how Matthew’s storyline turned out and enjoyed his character development and back story. The romance was slow burn and full of yearning. A fun mix of romance, fantasy and mystery that builds up to a big finish. I hope there’s more to come.

[Kiralee Paperbacks of a Wallflower · Rating 5 out of 5]

The plot twists were plot twisting!
I had read Book 1 thinking I had an idea of where Within the space of a heartbeat would go. I’m looking at you Parker! But no, Elise takes us on a journey to understand the backstory of Marielle/Flame or at least parts of her story & how having knowledge of her future & what happens to her in Neurovida in 2 years time has changed her previous relationships as well as what she knew to be true.

I honestly really enjoyed reading Mariella/Flame’s friendships develop within Neurovida with the main 5 characters Rose, Parker, Matthew’s, Bandit & Axis.

The time traveller of Matthew’s backstory is so pivotal & heartbreaking.


And that ending!!!!! I literally gasped out loud!

[Library of Melissa Jane · Rating 5 out of 5]

There’s something so special about a world that feels so thoughtfully built, where every detail adds something meaningful to the story. I really admire the way the author explores heavier topics with such a gentle touch, allowing the themes to speak for themselves without ever feeling overwhelming or too in your face. I already loved the first book but somehow this one managed to exceed every expectation. It felt richer, more impactful and just so beautifully done. A phenomenal sequel! The yearning 👀

[Brooke Jones · Rating 5 out of 5]

The second book in the series and have loved following the development of the characters and their stories.

Ella’s sense of finding her own power and inner strength in this book is inspiring.

The love story that develops is a gorgeous story of soulmates that is not the one you would expect. It is a heart warming story that ties into Ella’s story from the very beginning.