Code Name: Kingslayer: An Enemies to Lovers Romantic Suspense

by Delta James, Annie Carlisle

He was sent to eliminate me. He may be my only way out.

They call me Nocturne, female assassin, traitor, ghost. But I’m also Interpol’s last shot at taking down the Iron Choir, a shadow empire poised to ignite global chaos. One child is the key to their endgame, and if I don’t save her, the world burns.

My mission was protect the child and destroy the empire from within.
But then he shows up.

Archer Hayes. Cerberus’s blade in the dark. He doesn’t miss. He doesn’t hesitate.

His mission is kill Nocturne. Kill me.
He should have killed me the moment we crossed paths in the abandoned monastery in the Swiss Alps. Instead, he hesitated.

Now we’re stuck together in a deadly alliance, forced to trust each other as we dodge assassins, betrayals, and the sparks neither of us can control. The closer we get to the truth, the more dangerous this game becomes. And when the knife of betrayal slips too close, we’ll both have to trust the mission, or each other.

One choice will save the world. The other could set it on fire.

242 pages, Kindle Edition

Published January 30, 2026

About the author

As a USA Today bestselling romance author, Delta James aims to captivate readers with stories about complex heroines and the dominant alpha males who adore them. For Delta, romance is more than just a love story; it’s a journey with challenges and thrills along the way.

After creating a second chapter for herself that was dramatically different than the first, Delta now resides in Florida where she relaxes on warm summer evenings with her loveable pack of basset hounds as they watch the birds, squirrels, and lizards. When not crafting fast-paced tales, she enjoys horseback riding, hiking, and white-water rafting.

Her readers mean the world to her, and Delta tries to interact personally with as many messages as she can. If you’d like to chat or discuss books, you can find Delta on Instagram, Facebook, and in her private reader group https://www.facebook.com/groups/34898....

Reviews

[Sandy S · Rating 4 out of 5]

CODE NAME: KINGSLAYER is the third instalment contemporary adult CLUB OPUS NOIR erotic, romantic suspense series co-authored by Delta James and Annie Carlisle, set in Delta James’ CLUB SOUTHSIDE/ CERBERUS worlds. This is Cerberus agent Archer ‘Kingslayer’ Hayes, and female assassin Marissa ‘Nocturne’ Vale’s story line. CODE NAME: KINGSLAYER can be read as a stand alone without any difficulty. Any important information from the previous story lines is revealed where necessary.


Told from dual first person perspectives (Archer and Marissa) CODE NAME: KINGSLAYER follows Archer ‘Kingslayer’ Hayes as he is tasked with taking down Interpol’s female assassin turned rogue Marissa ‘Nocturne’ Vale. Undercover for five years, working with an organization known as the Iron Choir, Marissa will discover a plot to kidnap a young child, a plot that will find her reluctantly working with the team at Cerberus or face her own execution. Cerberus and Interpol believe Marissa has gone rogue, and in this, Archer Hayes must determine whether Marissa is a threat, or an asset to their latest assignment. A young child has been targeted, and Marissa and Archer will go undercover to ensure her safety.


The world building focuses on the reintegration of Marissa Vale as one of the good guys. Marissa believes she has lost herself to the darkness of the group known as the Iron Choir, but Archer is determined to prove she is worthy of love and a second chance.


The relationship between Marissa and Archer begins as an assignment; Archer has been ordered to terminate Marissa Vale but Archer seems something no one else has been able to see. As Marissa and Archer work together to uncover the truth, someone else is working from the inside, betraying them all. The $ex scenes are intimate, erotic, and intense, with some scenes of Dom/sub and rope play.


There is a large ensemble cast of colourful and desperate secondary and supporting characters including Logan Radcliffe and Vivian Black ( Code Name: Hunter), Cerberus owner Fitz. The requisite evil has many faces.


CODE NAME: KINGSLAYER is a story of madness and obsession, secrets and lies, power and control. The premise is character driven, dramatic and intense ; the romance is seductive and fated; the characters are desperate, dynamic and charismatic.


copy supplied for review

[Lucia · Rating 5 out of 5]

This is the third book in the series, and honestly, it was quite an emotional ride.

Let’s start with Marissa, she has been through so much to get where she is, to many people she is a traitor, but the truth is far more complex than it seems, when the life of a little girl is threatened Marissa has no choice and the truth finally comes to light, she infiltrated a criminal network to destroy it from the inside and that sacrifice cost her more than it gave her, along the way Marissa stopped existing and Nocturne was born, now she must face her past and work alongside Archer, a Cerberus agent who can not only tear down the walls she built, but also help her remember who she really is and find balance between Marissa and Nocturne

And then there is Archer, the man they call when things spiral out of control, his mission is simple, eliminate Marissa for her supposed betrayal, but everything changes when he finds her and discovers the truth behind her identity, a new mission begins and together they must work to protect and save an innocent child from falling into the hands of the Cardinal no matter the cost

Their personalities clash constantly, they are opposites in many ways, but when the lines between tactical duty and personal feelings start to blur there is no turning back, through ups and downs their feelings grow naturally, Marissa slowly opens up, allows Archer into her world and begins to heal a heart that had been broken for far too long, Archer in turn trusts her beyond appearances, gives her the security to be herself and shows her that it is okay to lean on someone else, she teaches him that he can trust, that feelings are real and that not everything has to be war and darkness

Together they prove they are stronger, they manage to protect the girl and strike an important blow against their enemies, their chemistry is simply incredible, built slowly but firmly, I loved seeing Marissa’s growth and honestly Archer is the kind of man who would burn the whole world just to keep her safe

In the end I deeply loved this book and that small preview at the end promises so much, dear Nitro I hope to know you much more through your story. ❤️❤️❤️❤️❤️

I received an advance review copy for free, and I am leaving this review voluntarily.

[Louise Car]

This action-packed, fast-paced, and addictive read was layered with complexity and carried an ominous vibe that kept my adrenaline high from start to finish. While I initially struggled to keep track of the many characters and their roles, it didn’t diminish my enjoyment of this masterfully intense, cloak-and-dagger romance.

Who is the real Marissa, an honest woman, a traitor, a ghost, or a villain determined to expose the truth? Confident and layered, her strength masks a vulnerability that slowly comes to light. For five years, working deep undercover for Interpol as Nocturne, a feared female assassin, she walked a dangerous line while gathering intelligence on the Iron Choir. Yet even in the criminal world, Marissa has boundaries she won’t cross. When a child becomes a target, she steps into the open, seeking help from the very man sent to eliminate her.

After years of living a lie, Marissa fears she no longer knows who she truly is. Surrendering control to Archer quiets her mind and makes her feel real again.

Archer Hayse, a Cerberus operator tasked with killing Marissa, begins to see the lines blur between Nocturne and the woman standing before him once she produces proof of her identity. Forced to work together to stop a mission that endangers a child, Archer struggles to maintain professional distance. Protective, possessive, and undeniably drawn to her, he crosses boundaries and claims her. I loved how his dominance brought Marissa calm through submission, while still respecting her skills and relying on her as an equal in their fight against evil.

Archer and Marissa are a chaotic yet perfect match, both haunted by past choices that refuse to stay buried. This intense, suspenseful, and imaginative romance delivers a plot twist I never saw coming. A true page-turner, with sizzling chemistry so sensual it left me melting into a puddle.

[Julie · Rating 5 out of 5]

This fast paced, action packed suspence will kick your adrenaline into overdrive as Archer (Kingslayer) and Marissa (Nocturne) finally come face to face. They've known about eachother for some time, but nothing compairs to the reality. Marissa has an uncanny ability to be anything to anyone, allowing her to blend into high risk situations. Archer is known for his ability to identify and eliminate/bring in high value targets. There's tension from the start, as neither is quite expecting what they get when they finally meet. Also, despite their initial objectives, when they start working cooperatively as a team their dynamics really shine. Archer is all Dom, and knows how to help Marissa find peace with the roles she's had to play in her life. His ability to see her as an equal in the field, and a submissive in private is validating and freeing for Marissa.
This book is well thought out, excellently paced and written with Delta's characteristics flair for action and heart. It's a must read addition to the series and can be read as a standalone. Previous books will give you a more stable foundation regarding the Iron Choir, but it's not mandatory for understanding or enjoyment (just giving you the option). Please, please check out this book, Archer and Marissa are on fire!
I was graciously provided a gift copy of this book through BookSirens and voluntarily provided this review. Happy Reading Y'all 📚

[Sue · Rating 5 out of 5]

A simply wonderful read, wonderful characters and a plot that held me riveted throughout this book
Marissa Vale is known by several names in this book by the persons that know of her they are the Nocturne, the phantom assassin and now she has been labelled by some as a traitor and has now gone her own way to find the proof needed to show that The Silent Canticle to gain evidence regarding The Iron Circle.
It seems that the target for their attention since she escaped at six years old Amelie and as Cerberus arrived, they have ordered Archer is advised by Fitz to eliminate her. However, when the scene fails to prove the evidence, she proceeds to give the evidence to Archer and it is taken to the Opus Noir, which operating undercover as a BDSM club in Monaco.
The story grows in suspense and the tension is growing rapidly, the tension and risks and threats are sky high and the slightest slip could bring this crashing down costing numerous lives. It s a real on the edge of the seat story and you cannot put this book down once you star reding until you discover the outcome.
I thoroughly enjoyed the book and look forward to reading any future publications; keep up all the wonderful writing.

[Denise · Rating 4 out of 5]

Marissa, aka Nocturne, has been working undercover to bring down the Iron Choir. She infiltrates one of their meeting places, copies records, barely escapes when Cerberus shows up and cocks up her exit. She knows someone from Cerburus will be coming for her so she goes somewhere they can easily find her.

Archer Hayes, aka Kingslayer, has been sent to kill Nocturne, an Interpol agent reportedly gone rogue. When he traces her to an Interpol safe house near Monte Carlo. When he arrives, she is waiting for him with a thumb drive full of evidence against the Iron Choir, including the planned abduction of the young daughter of the Interpol Deputy Director. The question is: can Cerberus trust the Intel? So starts a race to save a young girl and the partnership of Nocturne and Kingslayer.

This book felt really long. I guess because it seemed to drag. The story is a good one, though. Insta-love, of course, between two people who have been focused on their jobs and not their lives. Trust is a big part of the friction between them. I was given an advanced copy of this book by the author. My review is voluntary.

[Mariaan Belinfante · Rating 5 out of 5]

From the creativity whirlpool of Delta came another masterminded can't-put-it-down book. Marissa Vale known as Nocturne, the phantom assassin and now traitor. She infiltrated The Silent Canticle to get evidence on The Iron Circle. Their target is a 6yr old Amelie. As she escaped, Cerberus arrived. Archer is ordered by non other than Fitz to eliminate her, but the scene doesn't fit what he finds. She gives her Usb with evidence to Archer and is taken to Opus Noir, operating undercover of a BDSM club in Monaco. Evidence, but verification is needed. As the suspense escalates rapidly, tensions spike sky high, so does the off the charts chemistry as they now have to team up. Life and death moments, spice with a touch of BDSM, but more centred on the love growing in between the dangers. Nitro saw to a fitting end for Moreau, but the Conductor is still at large. I await the next book very impatiently... Hint Hint...
I received an advanced review copy and leave this review voluntary Thank you BookSirens

[Marie · Rating 5 out of 5]

This is the third in this series, with each about a different couple. In this story we meet Marissa, although she's known by a number of names. She is also thought to be a double agent, so now hunted by the best Cerberus has. Except not everything is as it seems, all she wants is to protect an innocent child. Archer never fails a mission, except this time his gut is telling him something isn't adding up. But orders are orders and he's supposed to follow, but the evidence says otherwise. The story is as suspenseful as the previous books. Both characters show that gut feelings are usually correct. But Archer struggles not following orders. While Marissa is focused on finding and eliminating the mole and saving a child from being kidnapped. Can they save her and eliminate the threat. Each book can be read as a standalone although I think it helps build a truer picture by reading each book.

[Katie · Rating 5 out of 5]

Archer and Marissa have both been in the shadow world for years, where “truth” and “trust” are situational. But both are tired of always wearing a mask and losing themselves to a persona. The work Cerberus does, eliminating threats moving behind the scenes, is still important to them but they need to a person beyond the persona. They were almost to the point of just following orders without questioning their instincts if something felt wrong. But Marissa has reached the end of her willingness to be a tool and has hit the line she won’t cross. And her determination to be more than Nocturne pulls Archer/Kingslayer along with her. Not easy or smooth, but their fight to overcome the walls that were necessary, but kept them isolated, was moving. Lots of action, emotion, danger and heat!

I received a free Advance Review Copy of this book and this is my voluntary review.

[Laure · Rating 4 out of 5]

Marissa Vale aka Nocturne former Interpol agent is considered a traitor, but she did what she had to do in order to expose a high-ranking official who is selling intelligence to the Iron Choir, a criminal organization ready to unleash chaos all over the globe. Archer Hayes, code name Kingslayer and Cerberus operative has a mission, find and eliminate Nocturne. Except when he catches up with her, he will hesitate to complete his assignment because the information she carries could save a young girls life. This is an exciting, action-packed, suspenseful and steamy read with compelling and unique characters that made it impossible to put this book down. I loved this book and happily recommend it to other readers.

I voluntarily reviewed a complimentary ARC provided by Book Sirens and the author.

[JigsawGirl · Rating 4 out of 5]

A fast paced story that kept me on the edge of my seat. Intriguing moments occurred while the Nocturne part of her personality tried to reconcile with her Marissa personality. Initially feeling like she was one or the other but couldn't be both, in walks Kingslayer.

I liked the way he accepted both parts of her personality and helped her come to terms with her entire self. There was plenty of action, suspense, danger, and romance. I enjoyed Marissa's strong independent nature and the fact that she could see the benefits of working with someone.

The ending was a good intro to Nitro's story which I am looking forward to reading.

I voluntarily read and reviewed an advanced copy of this book.

[Avis · Rating 5 out of 5]

What a rollercoaster ride of suspense and emotions.

We learn about Marissa's (Nocturne) past and how that affects the present. I loved that she tries to keep herself and Nocturne separate. And I love that Archer (Kingslayer) knows exactly how to help her achieve this. How to make her whole.

There mission was interesting . Something Marissa takes personally.

Well written. POV of both Marissa and Archer. Action and suspense from the first page. Steam to the eventual romance. I loved that Archer uses a different method to help her. That he seems to know what she needs.

Of course a HEA for them .

I received an advanced copy for free via Booksiren and am leaving my review voluntarily.

[ltfrom bc · Rating 5 out of 5]

Such a good book. Archer/Kingslayer and Marissa/Nocturne. All is not what it seems on the surface and Archer has learned to trust his instincts and is not afraid to challenge decisions. And it was a good thing he did, because he was ordered to deal with Nocturne in a final way. But as soon as he met her, he knew. He knew she was telling the truth. He knew that she was not who she seemed to the spy world. And he knew she was his. What followed was a very fast paced race that took them Morocco and straight into danger. This book keeps moving forward at a constant pace that makes it very realistic to read. Such a good story that is full of danger, suspense and the need for trust in world that that is not built on trust.

[Diana Page · Rating 5 out of 5]

Archer/Kingslayer and Marissa/Nocturne’s story is an interesting mix of Cerberus and Interpol working together and at cross purposes to save one little girl from kidnapping/being used to keep her father in line with their demands. These characters are some of the best that Delta James has written for this series since JJ and Fitz in my opinion. They fall for each other in record time, but end up nearly broken apart due to the manipulations of others. Great storyline and the locations were amazing and described in depth, Morocco’s descriptions makes me want to visit just to check out their markets and architecture. 5✨’s . I received an advance review copy for free, and I am leaving this review voluntarily.

[Karen · Rating 5 out of 5]

Instant Connection

He was sent to eliminate the problem but found someone who would become his world.

I loved how she opened up to him and let him see her vulnerability after years of losing herself in one mission after another.

This is a beautiful, well written, engaging story of betrayal, connection, trust and new beginnings amidst the danger and action of a mission that could go sideways at any time.

Fast-paced read with some sizzle that will keep you glued to each page as the story unfolds, bringing you into their world.

I voluntarily read and reviewed this book. All thoughts and opinions are my own.

[Elizabeth · Rating 4 out of 5]

I get anxious when I read books about undercover agents, I am always waiting for them to be found out. Fortunately, I did not have to wait long in this story as Archer knew instinctively that the person he was assigned to eliminate was not what she seemed and the Conductor apparently knew it as well. This story starts with explosive action and never lets up. Protecting a six year old girl is something neither of them ever anticipated and doing it while being betrayed by Interpol agents was even more disturbing. Trust plays an huge role in this story and it was nearly destroyed but love wings out and trust is restored.

[Jill · Rating 5 out of 5]

It’s an action packed drama with lots of danger and unexpected romance. I love that Archer is finally getting his story told and in the process, finds the one woman who makes him complete Marissa. As strong and dangerous as Archer is, Marissa is his equal when it comes to surviving. It’s a wonderful story and I loved every minute of it. I love the inclusion of Cerberus operatives and especially when Fitz and the others make appearances. This is a story worth reading along with the others in this series.

I received a free copy of this book via Booksirens and are voluntarily leaving a review.

[Shifty Bugger · Rating 5 out of 5]

I received an advance review copy for free, and I am leaving this review voluntarily.

This was another exhilarating book to read there was so much going on in this book I was hooked and all it took was Opus Noir, Fitzwallace with Cerberus and with the two main characters Archer and Marissa. Archer was given an order to eliminate. Nocturne was undercover trying to bring down the Iron Choir, then something happened to set your pants on fire. The twist and turns, action, drama, danger, enemies, Archer is running with Nocturne to keep her alive especially with the evidence. The slow burn between them and they never sore it coming.

[Debdutch · Rating 5 out of 5]

“Code Name: Kingslayer” by Delta James & Annie Carlisle

-A fast-paced, high-stakes romantic suspense packed with assassins, secrets, and explosive chemistry. I received a free copy and am voluntarily sharing my honest thoughts.

Archer and Marissa are dark, damaged, and perfectly matched, with a relationship that balances danger, trust, and heat. Intense action, strong worldbuilding, and a seductive emotional core make this a gripping, binge-worthy read.

This book features a large ensemble cast of supporting characters. It is cowritten by Delta James and Annie Carlisle who are two of my favorite authors.

[Knight Linda]

High action throughout this book as Archer was sent to eliminate a target Nocturne, but when he finds her, he discovered that she was not the enemy. Actually, she was on their side. They were all after the Iron Choir, and it's leader the conductor. Fitzpatrick leader of Cerberus assigned Archer and Nocturne as partners to gain entail on a planned kidnapping of Deputy Director Laurent's six year old daughter. Edge of your chair suspense, mystery, intrigue, with plenty of romance. A great lead in to the next book.

[Glenna Turney · Rating 5 out of 5]

As always Delta writes an amazing book. I did, me personally, get bogged down for maybe one chapter.

After that, this book moved with the usual excitement of the rescue and relationship between Archer and Marissa.

The meeting of Archer and Marissa was not one I was expecting. It was so worth finding out.

This series is exciting to read and you feel as though you personally are getting to know each man. His past, his present and a glimpse into his future.

*I received this ARC Kindle Book from BookSirens. Thank You!

[Deborah · Rating 4 out of 5]

Sometimes when an author does a series of books, it becomes the same book with different names. I am constantly amazed at the variety in this author's books built around the Cerberus entity. Some of them are in the US, some in Great Britain and others all over Europe. They are somewhat paramilitary thrillers, but there's always romance. This book, third in the Code Name series was particularly intriguing, not always quite believable, but thoroughly engaging. I highly recommend it.
I received an advance review copy for free, and I am leaving this review voluntarily.

[Melanie · Rating 5 out of 5]

Like ships that pass in the night they know of each other and have seen evidence of the other however, her light has grown dim in recent times and now might have gone dark.
Kingslayer is sent for Nocturne. Has she truly turned? He questions this so brings her in to talk is white black?
Two are better than one in their case.

I received this ARC from the author for free and am leaving this review voluntarily

[Angela · Rating 4 out of 5]

I like Marissa in all her incarnations. Whether as assassin or thief, traitor or patriot, heroine or villain, she played the part she needed in order to survive. It takes confidence and a talent to become all things to all people. Finding solace in Archer, being able to lean on his strength to let down her defences for a short time, and trusting in his integrity is only the beginning of their relationship.

[Mg Meredith · Rating 5 out of 5]

Code Name Kingslayer grabs your attention right away with a spicy but emotional story line that keeps you entertained with plenty of action drama and twisty unexpected surprises. Characters that are bold and over the top who always gets the job done but can put you in your feelings with a few well spoken words and actions.

I received a advance readers copy of this book and I am voluntarily leaving this review.

[Lindy D · Rating 5 out of 5]

I loved the backstory on this one. How the man sent out to terminate Nocturne had questions, and didn't act blindly, but searched for more.. It was very well written and taut with action and suspense! I loved how they both felt something immediately but moved slowly. I loved how Marissa followed her heart.. Great story.. happy ending..
I received an advance review copy for free, and I am leaving this review voluntarily.

[Judy · Rating 5 out of 5]

Okay ,words just won't do this story justice . If you've read any of the Cerberus stories you'll be familiar with who Nocturne is and let's not forget Archer the best eliminator Ceberus has. If you haven't she's a female assassin. This is her story and all she has been through. This had my emotions all over the place. I would give this more stars if I could.I received an advance review copy for free, and I am leaving this review voluntarily.

[Claire RC · Rating 5 out of 5]

Excellent story. Nocturne has to prove to Archer that she’s acting a part and not gone rogue. He’s been sent by Cerberus to assess the situation. Danger lurks all around and they need to move fast to prevent a kidnapping, question is can Archer and Cerberus trust Nocturne or is she playing them. Thrilling story with lots of action.

I received an advance review copy for free, and I am leaving this review voluntarily.

[Silke · Rating 3 out of 5]

Code Name Kingslayer is the 3rd book in the Opus Noir series. It can be read as a standalone even though there's a cast of recurring characters from previous books. Nocturne and Kingslayer's story has the author's trademark mix of pulse-pounding suspense and steamy sexy times, but this time, the suspense plot made no sense to me after the first skirmish. The action pulled me along nevertheless. I received an early copy and am leaving this review voluntarily and honestly.

[Linkie · Rating 4 out of 5]

She was burned and he was her only option, she took evidence to proof the she was not guilty. His team decided to investigate and they were a team. They were attracted to each other but she was alone for so long. Learning to trust each other and trusting in your partner. He cover was blown and they had to save a little girl from being kidnapped. In the end it all worked out and they were happy and in love