DCI John Meredith has two horrific murders to solve, both committed several years ago, and believed to be connected to a Russian drugs ring watched closely by the Secret Intelligence Service. This concerns Meredith, but keen to take on the challenge, he throws himself into the case. As a result Meredith's team find themselves under scrutiny, and perhaps for good reason, as it soon becomes clear that Meredith is keeping secrets from them. After placing himself in a compromising situation, Meredith becomes too close to the Russians with fatal consequences. Patsy Hodge has also been cleared to work for the Secret Intelligence Service, something that Meredith is less than happy about. Her first role, which she considers a boring one, is working for the Hatton brothers who are close to perfecting the world's most efficient body armour. The Hattons have a contract with the MOD, but they too have secrets which Patsy struggles to uncover. Once she does, she finds that her case is linked to the murders being investigated by Meredith, and lives are at risk. When Meredith is accused of murder, and his sergeant Louie Trump is suspended from duty, Patsy must decide whether to confront the Hattons and her superiors or place her trust in Meredith. Convinced that senior members of the SIS and possibly the government are involved in a cover up, Meredith arranges a meeting in the hope that he can reveal the truth. He does, but not everyone survives, and things will never be the same again.