In Twilight’s Promise, the eighth book in Sheila Kell’s Agents of HIS series, danger comes fast and trust is hard to find.
Title: Twilight's Promise
Author(s): Sheila Kell
Series: Agents of HIS #8
Published by Cunningham Publishing on January 31, 2026
Pages: 207
Genre(s): Romantic Suspense
Source: Author, Kindle Unlimited
Format: eArc, eBook 
Purchase: Amazon
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He was trained to protect. She was never meant to be his to save.Cybersecurity specialist Ava Sinclair lives by one trust no one. After uncovering a secret file buried inside a massive data breach, she becomes a target—and the only person standing between her and a bullet is a man she doesn’t know or trust.
Rob “Grits” Grimes, former Navy SEAL turned operative for Hamilton Investigation & Security, has one protect Ava at all costs. She’s brilliant, guarded, and nothing like his usual assignments. But when an ambush forces them off the grid, Grits realizes the threat is more than a hit job—it’s a conspiracy that could take down powerful players, including someone inside his own agency.
As danger closes in and Ava edges closer to the truth, sparks ignite between them. But the closer Grits gets to her heart, the harder it becomes to keep his own secrets buried.
Someone wants her silenced.
He’s the only one standing in their way.
But protecting her could cost him everything.
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Twilight’s Promise is the eighth book in Sheila Kell’s Agents of HIS series, and it works well as a standalone. This installment introduces Ava Sinclair, a cybersecurity expert, who uncovers a serious breach. A discovery that quickly escalates into danger. First, her laptop is stolen, then she becomes the target of an assassin. Grits, an HIS agent, steps in as her protector, setting up what should have been a tense, tightly woven romantic suspense.
To the book’s credit, there are moments where the uncertainty works well. There were parts of the story that had me guessing, and like Ava and Grits, I genuinely didn’t know who could be trusted. That level of doubt added to the tension and kept me engaged.
However, the larger issues stood out. Their backstory was limited, which made several emotional beats feel rushed. The story leans heavily on their connection without giving enough foundation to the more intense moments. In addition, some aspects of the plot simply aren’t clear. Key details are left unexplained, and a few questions remain unanswered by the end, which weakens the payoff of both the suspense and the romance.
Overall, the premise is solid, and the suspense delivers in parts, but the execution falls short in key areas. With tighter plotting, clearer explanations, and more developed character backstory, this could have been a much stronger installment. It’s not perfect, but it’s still entertaining and worth reading if you enjoy romance with a healthy dose of adrenaline.
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About Sheila Kell
Sheila Kell writes about the romantic men who leave women’s hearts pounding with a happily ever after built on memorable, adrenaline-pumping stories. Or, (since her editor attempts to cut down her long-windedness) simply “Smokin’ Hot Romance & Intrigue.” Her debut novel, His Desire (HIS Series #1), launched as an Amazon #1 romantic suspense bestseller and Top 100 overall, later winning the Readers’ Favorite award for best romantic suspense novel. As a Southern girl who has left behind her days with the U.S. Air Force, and as a University Vice President, she can usually be found nestled in the Mississippi woods, where she lives with her cats and all the strays that magically find her front door. When she isn’t writing, she has her nose in a good book, is dealing with the woodland critters who enjoy her back porch, or is wishing she had a genie to do her bidding.Sheila is a member of Romance Writers of America. For more information, visit Sheila’s website and subscribe to her newsletter:
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I’m glad the overall plot and characters were a hit even if the development was so-so.
That sounds pretty good.
Despite feeling rushed, it looks like the overall series delivers. Great review!