Starfire's Vow

by Megan Phillips

She saved the kingdom. Her soul will pay the price.

Newly crowned Queen of Serentyn, Lexa Andrever should be celebrating victory. Instead, she’s consumed by her failure to fully unleash Starfire. Now, with her mate, Griff, called to the border, Lexa’s only hope of understanding the elusive magic lies with Serentyn’s Master of Histories, Griff’s twin.

All the while, Cythraul—that ancient force of darkness—is laughing from afar…

From dusty tomes to cryptic clues left by unlikely sources, Lexa stumbles toward the key to a power few fully grasp. And, as she clings to snatches of precious time with Griff, Lexa begins to fear what is coming.

Because when Cythraul strikes, he won’t come for the kingdom. He’ll come for Lexa. Body, power…and soul.

Starfire’s Vow is the second book in The Soul of Serentyn trilogy—perfect for romantasy fans who love fated mates, found family, and on-page passion.

Kindle Edition

Expected publication December 15, 2026

About the author

Megan grew up in Maryland and now calls Virginia home—though her heart sets up camp wherever her characters drag it. With a degree in sociolinguistics and an ear for the way language shapes identity, she has spent years sketching voices, lives, and entire kingdoms in her mind. When she’s not writing, she shares her days with her husband, young son, Newfoundland dog, and horse. Starfire’s Heir is her debut novel.

Reviews

[Hira Khan · Rating 5 out of 5]

I legit crashed out and stared at the wall multiple times because WHAT JUST HAPPENED??!

I truly have no words. Starfire’s Heir was one of my top reads of 2026 and Starfire’s Vow surpassed that. This was super fast paced and had so many jaw dropping plot twists that I never saw coming. I need book 3 like yesterday because I’m never going to recover. This was an infinity star masterpiece.

[Erin Lawson · Rating 5 out of 5]

Received this book as an ARC from the author.

MEGAN. PHILLIPS. This book. Did I finish it or did it finish me?

I needed a day to process this story and compile my thoughts for a review. This book immediately picks up right at the end of book one, Starfire's Heir. The characters are still amazing and I loved every single one. Lexa, newly crowned queen and supposed savior of the world, is literally just doing her best and trying to figure it out. She was strong when she needed to be, and vulnerable in other times, and always so sarcastic. Griff is still top tier MMC material for me. He is broody, protective, also very sarcastic. I love a man who will burn down the world for his lady. That trope will always slay.

I read this book with friends and let me tell you the absolute crashing out that was had. The whole book was trying to piece it all together, which Megan does so beautifully. There were theories being thrown around left and right and I was not disappointed with how this book ended. AND THAT ENDING. Myt goodness. How am I supposed to wait for the next book?! HOW?

This book was incredible. Just the emotions I went through from start to finish absolutely made this a 5 star read for me. Books should make you feel things and I literally felt every emotion. It was the best time.

[Dominoe · Rating 5 out of 5]

Will review once I'm not sobbing uncontrollably.

6⭐️3🌶
This was one of the most spectacular sequels I've read in a very long time. I was blown away by the first book, I'm even more blown away by this one. It took me through every emotion known to man and possibly invented some new one. The connection between Griff and Lexa is unique in it's strength. Other main characters fall in love or whatever. Griff and Lexa join their very souls. The banter, flirting and humor is still present in this book, but the stakes have become much higher. This one feels more profound. The depth to which Lexa falls mentally is poignant. I wanted to reach inside the book myself, give her a hug and tell her it was going to be okay. The ending of this book absolutely gutted me. I doubt I'll ever get over it entirely. These characters are no longer fictional for me. Megan's writing is something very special. This book, this series is one of the best examples of what romance fantasy can be. Thank you to the author and her team for the advanced copy. It's strange thanking someone for ripping my heart out and stomping on it, but here I am none the less.

[Steffsbookrealm · Rating 5 out of 5]

Starfire’s Vow is book 2 of The Soul of Serentyn trilogy. Reviewing the second book in a series is always challenging when trying to avoid spoilers but I’ll do my best! This book picks up immediately after the battle at the end of book 1. Throughout this book, we learn more about the ancient prophesy naming Lexa as the chosen one to save Serentyn from the darkness.

There are so many twists and turns that kept me fully engaged from beginning to end! I love a good puzzle, especially when it involves piecing together clues about ancient prophecies throughout the story. We also get more of Griff and Lexa’s love story, along with the introduction of some new side characters! Book 2 also includes interesting chapter quotes from Garrett’s POV while book 1 was from Violet’s POV.

If you love chosen ones, fated mates, ancient prophecies, and heartbreaking sacrifices (and don’t mind shedding a few tears along the way), then you need to start this series!

[Ivana · Rating 5 out of 5]

If you haven’t picked up the first book, Starfire’s Heir, then THIS IS YOUR SIGN!!!

Holy smokes!! Starfire’s Vow is an emotional roller coaster! My heart hurts and I am bawling my eyes out!!😭😭😭😭 MEGAN!!! What have you done to me?!!!😭😭😭🤧

Be prepared with a giant box of tissues because you are going to be put through emotional hell with this one. The characters all go through so much and do so much growing.

Now on the lighter side, there are some beautiful moments that had my heart so full, and had me bawling out of pure joy. Again reference where I said emotional roller coaster!

I really appreciated that we picked up from where we left off in the first book. Being able to jump right back in was like I never left!

Starfire’s Vow had me HOOKED and I can’t wait for the next book! Megan better be able to mend my broken heart💔

[Kelly Gamboa · Rating 5 out of 5]

Thank you to the author for providing me with an earc.

So uhm. I have no soul or heart. This book destroyed me in the best way though haha. This book was incredible. We got more politics. We learned more about the magic system, more world building. Everything was just brilliant. Lexa is such a badass character who goes through so much but is so strong. Griff, I love him to death. He is always there for Lexa through the good and bad. Never leaving her. Like hello? Their love is so beautiful. There is some scenes that broke my heart and I could feel it hurting. Everything was incredible. The ending though? I'm scared. That hurted my heart and I'm scared for the finale. But this was amazing continuation and I loved it.

[Brittany · Rating 5 out of 5]

(I was graciously given an ARC copy in exchange for my HONEST review!)

WOW. WOW. WOW. I just. Wow. This book definitely does NOT suffer from “second book syndrome”. It was just as good, if not better, than book one which is hard to say since I LOVED book one!

Getting to watch Griff and Lexa’s relationship grow and evolve was just *chef’s kiss*. I love getting to see them getting angry, sad, heartbroken, and it just making them stronger every time.

I really love that the side characters actually have development and emotions and purpose. It makes it hard to pick a favorite though 😂

The plot twist at the end was brutal and delightfully unexpected and I’m not sure how I’m going to recover from it..

[Emily Hourihan · Rating 5 out of 5]

I loved it. I loved Lexa and Griff. I loved their romance. I did like exploring the other world for a while with Garret and Violet. I loved how Griff got Lexa back to reality. I also like how Finn did not forgive Lexa right away. I loved the romantic parts in the book. I also liked the high stakes action. The world building is phenomenal. The writing is lush and lyrical. I loved the banter of the main romantic relationship. My favorite side character still is Violet. She deserves her own storyline. I felt like there is so much more to story to read from her PoV and from the past. Overall, I can’t wait to see where the trilogy ends, and how they solved their problems.

[Killian Maddox · Rating 5 out of 5]

Starfire’s Vow shattered my heart into teeny tiny pieces. Returning to Serentyn was emotional, heartbreaking, and still so beautiful. I'm still big mad about miscommunication/not communicating BUT it made the impact of the ending stronger, so I'll allow it 😂.

As a book 2 in a trilogy it kept the pace up, increased the stakes, and dropped us off a cliff with no parachute. I am feral for book 3 to drop!

I know who *I* believe is the true Soul of Serentyn (tho my phone keeps wanting it to be soup, and man those are some wild ingredients) but you'll need to read for yourself and decide!

[Melissa · Rating 5 out of 5]

You know how sometimes an ending hits you so heard that you forget everything you've just read? That's what's just happened to me.

This book was brilliant and incredibly heart wrenching. Relationships are tested to the max, and have you wondering how they will possibly make it through.

Fans of Throne of Glass, you will like this series!