Protect Thy Heart

by Marilyn Don

They were never meant to get this close.
But now the lies are too big to outrun.

The mission was supposed to be simple. Keep the detail tight. Stay focused. Don’t get involved.
But lines were crossed. Trust was broken. And what began as a partnership is now something neither of them knows how to name.

In the final book of the Desires & Duties Duet, Arden and Holden face everything they tried to ignore—the betrayal, the fallout, and the pull that’s only grown harder to resist.

Genres: Enemies To Lovers, Dark Romance

274 pages, Kindle Edition

Published December 18, 2025

About the author

Marilyn Don writes romance for the daydreamers and trope-lovers who crave a little chaos with their love stories. When she's not writing, she's either working her 9 to 5, trying to finish her own degree, or chasing her four-going-on-forty-year-old around Atlanta. She enjoys reading way past midnight, watching an emotional anime, and rewatching her favorite comfort shows.

Reviews

[Tasia H · Rating 5 out of 5]

I love the build of Arden’s character. How resilient yet consequential she is. She’s the embodiment of beating the odds and I appreciate that. The whole book is engaging and constantly pulling you in. The tension is thick yet easy to swallow. The anger feels justified but as I read, I questioned myself. Wondering if my finger should’ve been pointing so heavy. The attraction between Arden and Holden is also intriguing. The suspense between the two is leveled beautifully and portrayed perfectly. And don’t get me started on the hurt and betrayal. I found myself torn between realities as stories were passed by all. Questioning who to trust and if the truth was really pushed out. I’ll admit, the first chapter had me gasping, searching for more and it was truly delivered. The first page itself drew me in a gave me a promise that this book truly fulfills. Marylin Don is a true author and this book is like a delicacy that I can’t get enough of it. Believe when I say it pulls you in and keeps you there.

[Dymon Knapps · Rating 3 out of 5]

Rating: 3.75
Spice: 🌶️🌶️

Arden and Holden's character development was everything I hoped for. There were a lot more emotionally intimate moments between them that showed the attraction wasn't purely just physical. I also loved the scene between Leo and Arden finally getting to talk one-on-one one.

I really enjoyed the series and thought the character development was much stronger than in the first book. By the end, I found myself wanting a little more, especially in the epilogues, which left me with a few lingering questions. Because of that, this was a 3.75⭐ read for me, but with more closure, it could have easily been a 4⭐.

[Lyndsay Blackman · Rating 5 out of 5]

I have waited for this book to see where the cliff hanger from book 1 would go.

What can I say!? This was the ending I was wanting and hoping for!!! Holden and Arden were a power couple before you even knew if they would end up together or not! They went through so much to get where they ended up. Of course this kept me wanting to read and not put down because the suspense of everything going on had me wanting and needing to see, what happened next.

This Duet is one I highly recommend!

[Nicole၄၃ · Rating 4 out of 5]

I’m so happy to finally have answers after the first book ended on such a cliffhanger. Holden continues to do anything to protect Arden and it’s almost too much. The intensity they have makes the spice that much hotter. There is a lot and I mean a lot of spicy scenes.
Honestly you have to read this duet. I still had questions at the end around Arden’s family but still found it a great read.