The brutal murder of a fellow officer still hangs over Harrogate police. But the killing isn’t over.

A killer is stalking Harrogate—and choosing his victims carefully.

When a series of gruesome murders reveals a disturbing pattern, detectives fear a vigilante killer is on the loose. Paedophiles. Drug dealers. Addicts. Someone is targeting the people others would rather forget, and the body count is rising.

As Operation Caterpillar takes the fight to county lines gangs, DCI Rosie Marks faces her most dangerous battle yet. A mole inside Harrogate Police Station has been selling confidential intelligence to notorious OCG boss Brian Hazell—and Rosie has sworn to uncover the traitor. If she fails, she will walk away from the job she’s devoted her life to.

With bodies mounting, alliances fracturing, and Hazell tightening his grip, Rosie must race to stop a killer and finally bring her greatest enemy to justice. But the truth she’s hunting may cost her more than her career.

Everything comes to a head.

Secrets will be exposed.

And Rosie’s unfinished business can no longer stay buried.

A gripping, high-stakes instalment in the Rosie Marks crime drama series.