CXVI Trilogy Books in Order

The CXVI Trilogy is a British conspiracy thriller series that starts as a murder investigation and keeps widening. In The Beginning of the End, Detective Superintendent Greg Woods and his team are pulled into a case involving a murdered colleague, other suspicious deaths, and a new detective sergeant, Maria Barnes, whose reputation arrives before she does. From the start, the books ask two questions at once: who is killing people, and what is Barnes really connected to?

Greg is the grounded center of the series. He is experienced, stubborn, and used to working inside the rules, at least until the rules stop helping. Maria is harder to pin down. She is highly capable, secretive, and tied to the case in ways that keep both the police and the Secret Intelligence Service on edge. Their partnership gives the trilogy most of its energy. Greg wants answers. Maria often seems to know more than she can safely say.

This is not a tidy whodunit.

Across the three books, the investigation keeps pushing outward into serial murder, covert interests, political power, and buried information that some very dangerous people want to keep hidden. Secrets Broken raises the pressure by making Maria herself the focus of the search, linking her to the murder of a former Home Secretary, and trapping her with the ruthless Freddy Williams. By Desperate Measures, Greg is retired, worn down, and still searching for Maria years later. Faulkner-Brown and other adversarial figures help keep the atmosphere tense, because very little in this story stays settled for long.

The tone sits somewhere between police procedural and spy thriller. There are detectives, crime scenes, and casework, but there is also undercover pressure, intelligence-service interference, bluffing, missing people, and the constant feeling that official explanations are never the whole story. The stakes do not stay local for long. What begins with individual murders gradually points toward something embedded inside government and, by the end, something that threatens wider security.

Readers who like this trilogy usually come for momentum. Smith likes cliff-edge decisions, uneasy alliances, and characters who have to act before they fully understand what they are stepping into. Greg is not a glamorous action hero, and that helps. His persistence, fatigue, and refusal to let go give the trilogy its emotional backbone, while Maria brings mystery and risk every time the plot seems ready to settle. Read these books in order: The Beginning of the End, Secrets Broken, then Desperate Measures.