Why I Killed My Best Friend

by Nicki Grace

Have you ever done something so heinous that you can barely stand to look at yourself?

I did, and honestly, I don’t recommend it—especially now that I’m the prime suspect for the murder of my friend Jules.

But you see, Jules wasn’t entirely innocent. She lied. She betrayed, and she collected enemies like souvenirs, and sometimes, I was one of them.

Yet, the question is, did she deserve to die? Probably.

With all the secrets that have been concealed, the truth surrounding Jules' death is far more complex than it appears, and I intend to confess everything.

One thing to remember, though, they say the devil is in the details, but that’s flawed thinking when people only see the details they want. Which is why no one will notice when I tell them the one detail that matters most... WHY I KILLED MY BEST FRIEND.

200 pages, Kindle Edition

Published December 23, 2025

About the author

Nicki Grace is an author, wife, mother and philanthropist. She has a Bachelor′s Degree in Business Administration and a Master’s Degree in Creative Marketing and Entrepreneurship. She enjoys using her skills and background to teach others how to be the best version of themselves.
You can read other books by Nicki Grace at nickigracenovels.com

Reviews

[Sarah * Between the Lines Book Reviews · Rating 5 out of 5]

I absolutely devoured this book. This is a gripping psychological thriller that will have you guessing to the very end and have your mind blown. WOW just WOW! I laughed at times, and had my heart wrenching for Mouse (Melissa) in other times, and so much more.
If you are a fan of Nicki Grace and her Damsel series this book you will LOVE as it ties in with Sidney!I was so excited when I saw Sidney appear and then see a serial killer that appeared in Sidneys story in this one. Makes me want to go back and re-read book #2 of the Damsel series, The Darkest Damsel.

[Karen Brooks - TheTxLitChic · Rating 5 out of 5]

Why I Killed My Best Friend

~Nicki Grace

“Share this book with your best friend—because sometimes the only answer is to kill for them… or to simply kill them.”

What. The. Actual. F*%#?! My brain is still reeling.

Nicki Grace has absolutely outdone herself with Why I Killed My Best Friend. If you want emotion - check. Drama - check. Murd3r - check. Unhinged chaos – checkity, check, check, check!

I actually went back and reread sections just to make sure I’d comprehended what I thought I’d just read. This review will stay light on details because, trust me, this is one story you need to experience blind. All I’ll say is: by the time you finish, you’ll question everyone around you… maybe even yourself.

Grace kicks things off with a chilling prologue - Melissa “Mouse” Gillespie sits in an interrogation room across from Detective Mueller, accused of murdering her best friend, Julianna “Jules” Cardozo, whose body was found behind her favorite bar, Banter. To complicate matters, a serial predator is on the loose, targeting women who look disturbingly similar to both Mouse and Jules.

Told through shifting POVs and timelines, Grace gives us a layered, emotional deep-dive into Mouse’s connections - with Jules, with Rowan (her overprotective game-developer boyfriend), with Benji (her trauma-stricken, drug-using brother), and with Dr. Loomis (the third therapist to attempt to untangle her past) just to name a few.

Each character feels raw, real, and vividly human. Their flaws, pain, and tangled relationships pull you straight into their world until you can feel their tension. Mouse herself is a standout - complex, scarred, and chaotic in the best possible way.

Grace weaves dark suspense, razor-sharp pacing, and cinematic detail into a story that’s equal parts thriller and emotional gut punch - sprinkled with moments of biting humor and topped with twists so wild they’ll make your head spin.

I went into Why I Killed My Best Friend expecting brilliance - Grace always delivers - but I wasn’t ready for how deliciously demented this treat would be. If you crave a psychological thriller that grabs you from the prologue and refuses to let go until the final page, leaving you slightly breathless (and possibly side-eyeing your bestie)… this is the one.

Releasing December 23, 2025 – Pre-order now, and prepare yourself.

[Sarah Ross · Rating 5 out of 5]

Ahhhh!!! Loved this one! Couldn’t stop reading. The ending was twisty & so good

[Tanisha Stewart · Rating 5 out of 5]

Wild tale

This was a twisted and wild tale but I'm here for it. This is my second or third read by this author and I cannot wait for more!

[Shauntelle (shauntellereads) · Rating 5 out of 5]

Nicki Grace really came for my nerves with this one. I sat down thinking I’d read a few chapters and suddenly I’m halfway through, fully stressed, fully invested, and questioning everyone on the page like they personally wronged me.

Mouse and Jules’ story is told across past and present, and the way Grace threads their friendship together is equal parts emotional and unsettling. Mouse is messy, loyal, traumatized, and so painfully human that you can feel her anxiety sitting in your chest. Jules is complicated in a way that makes you love her one moment and doubt her the next. Their bond is intense, toxic, tender, and terrifying all at once, and I was eating it up.

The suspense stays high from start to finish. Every chapter ends on a note that makes you say “one more,” and suddenly it’s two in the morning. And those twists at the end? Back to back chaos in the best way possible. The title hits different once you see how everything unravels.

Fast, twisty, emotional, and impossible to put down. Nicki Grace knows how to write psychological tension that grabs you by the throat and doesn’t let go.

Five stars. This one had me side-eyeing every character and maybe even a few people in real life.

[Matt · Rating 5 out of 5]

Melissa's (Mouse's) life is in pieces. Her best friend is dead and she's now the prime suspect. The police don't know Jules the way Mouse does. Jules was no saint and her list of enemies could stretch to the moon and back. Her unique relationship with Mouse definitely doesn't help matters. Jules's toxic life frequently spilled over into Mouse's life with some dire consequences. Secrets, lies, and mystery swirl together to keep you guessing up to the very last page. The truth behind Jules's death is far more complicated than anyone realizes.

If you've read Nicki's Twisted Damsel series, you'll notice quickly this is in the same universe and we even have some of the characters appear here like old friends. The kind of old friends you see at a party where you quickly duck out of the room and hope they don't see you. Mouse gives us just enough with each sentence to keep you pulled in without revealing too much of herself and the night Jules died. With friends like her, who needs enemies?

Yet another great read from Nicki Grace!

[Lama Dabbagh · Rating 5 out of 5]

Trust No One: Nicki Grace Delivers a Killer Story

⭐️⭐️⭐️⭐️⭐️

I had the great opportunity to read an ARC copy of Why I Killed My Best Friend by Nicki Grace, and I finished it in just two nights!

The story follows Melissa (Mouse) and her best friend Jules, told through dual timelines of the past and present. From the very beginning, it had me questioning everyone and trusting no one, constantly wondering who the killer really is.

I really enjoyed Grace’s writing style and the way she introduced each character. Even though the story revolves around murder, betrayal, and revenge, there’s a clever thread of dark humour that genuinely made me laugh.

The ending delivers not one but two shocking twists, both chilling and brilliant, leaving me on an absolute adrenaline rush.

Why I Killed My Best Friend is a gripping psychological thriller that keeps you turning the pages right to the very end. Nicki Grace, an indie author, truly deserves recognition for her incredible work.
I look forward to her future work 😁

[Read With Lorena · Rating 5 out of 5]

Why I Killed My Best Friend was absolutely jaw dropping! I couldn’t put it down. Nicki Grace pulled me into the story immediately without dragging anything out. I’ve read a lot of thrillers where the ending feels rushed, but not this one. This ending was well thought out, sharp, and incredibly meticulous.

The characters were brilliantly written, and the twists were CRAZY in the best possible way. Every time I thought I had something figured out, I was proven wrong. Truly a gripping read from start to finish!

[Daniel Good · Rating 4 out of 5]

Okay wow!! This book had me hooked from the start! Every single chapter ended in a way that made it impossible to stop reading. And when that one plot twist hit? I was literally like WTFFFF! 😭🔥

Nicki Grace did such a good job tying everything together by the end. The ending not only wrapped things up perfectly, but it also made the title click in such a smart, satisfying way.

If you’re looking for a fast, twisty, and totally entertaining read that’ll keep you flipping pages late into the night, I definitely recommend picking this one up!

[Jine · Rating 5 out of 5]

When you sit and finish the whole thing in one go you know it’s a goodie!
First off didn’t realize Sydney from this book was the Sydney from her other series which I love!
This one is a little messed up in the best way possible! Her books always grab you and don’t let go until the very end and the fmc is normally messed up but you root for them anyway! You will definitely want to check this one out when it’s released it’s fantastic!

[Julie Kruger · Rating 5 out of 5]

This book is amazing! It was hard to put down and it kept me guessing the whole time until the very end. The twists were unpredictable and totally threw me. If you’ve read The Twisted Damsel and The Darkest Damsel this is a must read. It ties up all the loose ends. I highly recommend.

[Amethyst Maxey · Rating 5 out of 5]

Nicki Grace is quickly becoming one of my favorite thriller authors. Her books are so fast paced and page turners that you don’t want to put them down. This was no exception. I thought I knew who dunnit but of course I was wrong as always.

Mouse is accused of killer her best friend Jules but did she? This was a twisty book. I love how the author tied into her other series with Sidney and her kidnapping from the Damsel series.

[Julie Lima]

I cannot wait until this book comes out. Read a start of the story and it had my attention and even laughed out loud at one part about the buttons.It looks like it will be all sorts of emotions. After a some research it looks like "Nicki Grace"Why I Killed My Best Friend is going to be an author to read/follow.

[TJ Turns Pages · Rating 5 out of 5]

Why I Killed My Best Friend by Nicki Grace follows Melissa, known as Mouse, as she’s interrogated as the prime suspect in the death of her longtime friend, Jules. Through a sequence of sharply drawn flashbacks, Grace unravels the history of their volatile bond, exposing the kind of loyalty that feels more like a trap and a friendship that curdled long before the night Jules died.

Mouse and Jules have known each other since kindergarten, and their shared past is marked by chaos, grief, and poor decisions. As Mouse grows up and finally begins to see her life with more clarity, Jules clings to the reckless habits that have defined her for years, pulling Mouse back into patterns she’s desperate to escape. Watching Mouse confront the truth about who Jules really was forces the reader to consider the central question: Did she do it?

I found the novel genuinely compelling. Mouse is a strong and memorable narrator whose voice feels raw and lived-in. Her childhood trauma and the relentless loss she’s suffered shape her in ways that make her choices understandable, even when they’re messy. Grace treats these emotional threads with a steady hand, showing how easy it is to numb yourself until the consequences close in.

The story moves quickly, and I tore through it in two days. The pacing is tight, the chapter transitions feel seamless, and some moments genuinely shocked me. Grace’s writing is confident, atmospheric, and layered with tension. She balances voice, structure, and character work with a control that made the book hard to put down. Her ability to capture the psychology of toxic friendship and the slow unraveling of self is impressive, and it’s clear she has a strong command of both storytelling and tone.

I’m excited to read more from her.

Thank you to Nicki Grace, Ayee C. Pa, and By Moonlight Words Literary Services for providing this advance reader copy free of charge. I am leaving this review voluntarily.

[Brenda Brown · Rating 5 out of 5]

Want to read a book with lots of twists, turns and 😯 moments? You need to read Why I Killed My Best Friend by Author Nicki Grace. Wow, what did I just read!!

Mouse (Melissa) has been friends with Jules since grade school. Always doing risky things together, but Jules is the biggest risk taker and betrays Mouse in the worst way, but does that mean Mouse kills Jules?? There are tons of surprises in this book, and I'm not going to tell! No way, even though I really want to and it's wanting to burst out of me, I can't say. You will need to read it yourself!!

About this book:
Genre/tropes: Psychological Thriller / Dual timelines / Whodunnit

Have you ever done something so heinous that you can barely stand to look at yourself?

I did, and honestly, I don’t recommend it—especially now that I’m the prime suspect for the mürder of my friend Jules.
But you see, Jules wasn’t entirely innocent. She lied. She betrayed, and she collected enemies like souvenirs, and sometimes, I was one of them.
Yet, the question is, did she deserve to dië? Probably.
With all the secrets that have been concealed, the truth surrounding Jules’ dëath is far more complex than it appears, and I intend to confess everything.
One thing to remember, though, they say the devil is in the details, but that’s flawed thinking when people only see the details they want. Which is why no one will notice when I tell them the one detail that matters most... WHY I K!LLED MY BEST FRIEND.

You have to read this book! Releases 12/23/25
https://a.co/d/gLAr4qN

While you wait, read the twisted series!! They are just as good!

The Twisted Damsel- Book 1: https://a.co/d/0UtZn5e

The Darkest Damsel - Book 2: https://a.co/d/3jnyz8A

[Jessica Clemons · Rating 5 out of 5]

Nicki has done it again. Why I Killed My Best Friend is a phenomenal addition to the Twisted Damsel universe — and if you loved Sidney, you’re going to fall hard for Mouse. This book is beautifully written, darkly emotional, and absolutely gripping from page one.

Just when I thought I had everything figured out… I didn’t. Not even close. The twists hit hard, the suspense is relentless, and the confusion — in the best, most intentional way — keeps you glued to every chapter. Very rarely does a plot twist actually get me, but this one blindsided me in the most satisfying way.

And that ending? It cut deep. Nicki crafted something raw, sharp, and unforgettable. I may have shed a tear or two — but we don’t need to talk about that.

If you’re a fan of psychological suspense or twisty thrillers, this is absolutely one you shouldn’t miss. Highly, highly recommended.

[Ag · Rating 5 out of 5]

Have you read any of the other books by Nicki Grace? If you have, and if you like those, you will LOVE this one too.
Have you read her Damsel series? Remember Mouse? There wasn’t much about her; she was just a minor side character there, but this book is all about her. This is a Mouse book, if I may.
It is as wild as Nicki Grace writes them. It is as unhinged as you’d expect it to be. Rest assured, not a single hinge was damaged in the process of writing or reading this book – those just weren’t present at all; therefore, no hinge damage happened.
If you want cute, if you want tame, then this isn’t for you. Stay away, ok?
Other than everything unhinged, the story is actually a sad one and an emotional one. There is also suspense and tension, and at times it feels like you are missing something, like you aren’t being told something that is happening behind the scenes or inside some heads, but that’s all a part of the story, a part of the charm, a part of what makes this story what it is.
Also, that wicked dark sense of humor that’s there all throughout the book, that is gold, that is pure gold.

[Detra.honeyblonde · Rating 4 out of 5]

Why I Killed My Best Friend had me locked in from page one. I thought I knew where the story was going—NOPE. Every twist came flying out of left field, and by the time everything fused together at the end? My jaw was on the floor.

I devoured this ARC in two days. Melissa and Jules’ dual timelines kept me suspicious of everybody. Nicki Grace had me side-eyeing every character and trusting NO ONE.

Her writing is sharp, dark, and even funny in the sneakiest ways. And that ending… TWO twists. Both insane. Both brilliant. I had an adrenaline rush trying to process it all.

This thriller is fast, chaotic in the best way, and absolutely unputdownable. Nicki Grace snapped with this one, and I’m already waiting for whatever she does next.

[Tammy Bishof · Rating 5 out of 5]

Wow! I finished this book in a mere 5 hours. I did not want to put it down! I relate to the main character, Mouse, in the way that her life and past experiences have shaped who she is as a person.

I absolutely loved the dark humor that author Nicki Grace has. This was my first book by her, but I'll definitely be reading all of her others now!

This book will definitely have you question yourself about whodunnit!!! Trust NO ONE! Did she really kill her best friend? You'll have to read this unputdownable thriller to find out! Make sure you set enough time aside because you are not going to want to put it down!

[Marilena EchoHawk · Rating 4 out of 5]

Why I K!lled My Best Friend is more of a whodunit than a thriller, and it kept me completely engaged from start to finish. The twists are clever, unexpected, and sometimes shocking, and even when the story feels a little far-fetched, it’s impossible not to get swept up in the ride. I loved how every detail, no matter how small, ties together by the end it makes the whole story feel smartly constructed and satisfying.
Nicki Grace’s writing is clear, engaging, and so easy to read, making this book a perfect binge-read
Thank you to Nicki Grace for the ARC , I really enjoyed this read!

[Mercedes Rocha · Rating 4 out of 5]

Just finished this book.
The story was really, it starts with you meeting Mouse and Moose is an unreliable narrator who is sorta also telling you the truth lol.
She describes her Boyfriend Rowan as perfect nice caring protective. But as soon as she said he hates my best friend Jules I was like ya he fucked her….
Jules is that friend that’s more your enemy your hater than your best friend.
Plot was well done. I love how everything came together and you weren’t stuck with lingering questions that would never get answered. Overall a very good story I highly enjoyed .

[Shellyann Paape · Rating 5 out of 5]

Holy smokes, what a ride. A whole dun it mystery.

A whirlwind from the very beginning. Was questioning things early on, but was like “nah, you’re wrong.” Few times I went back and reread a few pages because I was like “uh, did you seriously just read that.”

Now here I sit, with questions. Mainly WTH did I just read, and when can I expect to read book 2?!?

In the meantime, I think I am going to learn about Sidney in The Twister Series

[Nikki B. · Rating 4 out of 5]

Why I killed My Best Friend is a fast paces psychological thriller that will keep you hooked to the story. Mouse is accused of killing her best friend. She has the motive and the time. But she swears she didn't do it.
This story is twisty and captivating. I loved that Sidney made a reappearance in this one. Sidney always brings that little extra flare to the story.
The story is intriguing, captivating and very well written with a few twists. I highly recommend giving this one read.

[Donna Williams · Rating 5 out of 5]

“Share this book with your best friend—because sometimes the only answer is to kill for them… or to simply kill them.”

What. The. Actual. F*%#?! My brain is still reeling from everything that happened in this book. Nicki Grace has absolutely outdone herself with Why I Killed My Best Friend. If you want emotion - check. Drama - check. Murd3r - check. Unhinged - triple check. This book literally had me hooked from start to finish. I literally devoured it and wanted more.

[Nicole Neice · Rating 4 out of 5]

I’ll admit, I was really unsure about this book when I first started. Not sure it was going to be my vibe.

MAN WAS I WRONG!

Before I knew it I was on the edge of my seat asking my self what the actual F! I was hooked and could not put it down! Just when I thought I knew what was coming, BAM Nicki hits you with plot twist after plot twist!

Why I Killed My Best Friend releases on December 23rd but you can pre order it now! I promise you want to add this to your TBR immediately!

[The Book Ssirren · Rating 5 out of 5]

This was one Hell of a book! talk about a mind twisting psychological thriller.
I was on the edge of my seat the entire time. there was nothing in the world that could take me away from this read. like every time i thought I had an idea about what was going on, I was dead Wrong. the twists and turns, the mind games, just blew me away.
I have to say, this book is so engrossing, that is my all time thriller read this year.
if you've not read this, go get a copy now! you will have zero regrets.

[LaGina · Rating 5 out of 5]

I was three chapters in and life hit me for a loop so I had to back away for a few days. But when I picked it up again last night it was what the doctor ordered! As a murder mystery person this was right up my alley. The characters and their surroundings described so go this book played like a movie in my head. It was awesome. This was a new to me author but now on my list of will read! Oh you want to know about the book itself....you'll never guess who done it till the end. I was SHOCKED!

[Mary · Rating 5 out of 5]

This is a wickedly brilliant, unputdownable psychological thriller that deserves every one of its five stars! From the very first page, I was completely hooked by the story. I did not want to put this down to go to sleep! I questioned everyone, I was on the edge for most of the book. I love the dark humor that was added in as well. I highly recommend this book. I can’t wait to read more from Nicki Grace.

[M Deni · Rating 5 out of 5]

“Ah damn!” was my exact words at the very end. This author is good at making you think one thing when it’s another. The questions you have throughout this story keeps you tuned in and she ties it altogether. It’s like you’re trying to solve a murder mystery through the entire story. I loved it!!!!

[Suzan Larson · Rating 4 out of 5]

This is a great story with more twists then well then the twist! All the twists tie up very nicely at the end, I’ll never get how that’s done. I guess that’s why I’m a reader. I loved these characters, they are all flawed, but you will love most of them anyway! This story will take you on a journey few of us will take, but it’s a fun one. 41/2 stars for this one.