Book Review: The Agency – Operation Delta by Anastasia Thomas

My rating: 5 of 5 stars


The Agency: Operation Delta drops readers into a tense, fast-paced world of espionage, biological threats, and shifting moral lines. At the center is Vanessa, a genetically enhanced agent recovering from a botched mission and a viral infection that’s more than it seems. As she digs deeper into a mess of political cover-ups and personal regrets, Detective Miller is chasing his own demons while investigating a string of murders that seem tied to Vanessa’s world.

What makes this book stand out isn’t just the action (though there’s plenty of that)—it’s the emotional weight behind it. Vanessa’s vulnerability, guilt, and quiet strength give the story real depth. Watching her wrestle with loyalty, identity, and what it means to do the right thing adds a compelling human element to the spy-thriller formula.

The pacing is strong, the writing keeps things moving, and the tension builds in all the right places. If there’s any downside, it’s that a few of the side characters could use a little more fleshing out—but the core of the story is solid and engaging.

This probably isn’t for readers who want their heroes purely good or bad, or who prefer lighter thrillers. But if you enjoy morally complex characters, ethical dilemmas, and stories that challenge your perspective—this one’s for you. Think Jason Bourne with more heart and less flash.

The Agency: Operation Delta delivers a smart, gritty take on the spy genre, and it’s easy to imagine this book gaining a loyal following.



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