DI Kate Simms Books in Order

The DI Kate Simms books stay close to a detective who is good at her job and still paying for one decision that went wrong. Before Everyone Lies, Kate helped Professor Nick Fennimore when his family life collapsed into murder and disappearance. She acted out of loyalty and judgement, and the result was a demotion that stalled her career. By the time the series opens, she is tough, capable, and under no illusion about how quickly a police force can turn on its own. She is not treated like a star detective, and that matters.

That makes her easy to root for from the first page.

Kate works inside systems, which means these books are never only about clues. She has bosses who sideline awkward cases, colleagues she cannot fully trust, and public pressure that changes what an investigation is allowed to be. In Everyone Lies, she is handed suspicious deaths that other people would be happy to wave away. What follows is a Manchester case full of institutional defensiveness, media noise, and evidence that keeps refusing to behave.

Nick Fennimore is central to the series, but Kate is the one who gives it shape. She knows what he can do, and she knows the cost of being seen beside him. Their history adds heat to almost every conversation. Sometimes he is the expert she needs. Sometimes he is the last person she wants near a case. The books are good at holding both truths at once, which is a big part of why the partnership feels sharp rather than cosy.

Kate carries the emotional weather of the series.

In Believe No One, she is on assignment with St Louis PD, reviewing cold cases and sharing methods, which lets the story widen from Manchester streets to a much larger serial investigation reaching into Oklahoma. In Truth Will Out, she is back in the UK, facing a child abduction case while trying to push past official resistance. Manchester matters as a lived-in setting, not a generic backdrop, and the American detour makes Kate's outsider status even sharper.

The tone is procedural, forensic, and personal all at once. There is real attention to scene work, timelines, lab results, and the drag of paperwork, but AD Garrett never loses sight of the people caught in the machinery. Progress tends to come inch by inch. Victims are often women and children on the edge of public sympathy, and Kate's refusal to look away gives the series its moral center. If you like detectives who win by persistence, judgement, and sheer stubbornness, DI Kate Simms is exactly that kind of lead.