A woman is killed on her way to a fertility clinic which religious protesters are targeting. Reid finds herself leading the team to find her killer.

Murder strikes close to home for the team when DCI Matt Burke's elderly father is found dead in suspicious circumstances. What appears to be a straightforward case of liver failure takes a sinister turn when it is discovered that Andrew Burke died of a heroin overdose. Against police regulations, DCI Burke is determined to solve the case.

A mutilated body is discovered by some standing stones on a remote island. Ross and Reid travel to the island to investigate, but find the inhabitants to be wary of outsiders and seemingly reluctant to assist. Returning to Glasgow with the body, Burke and Fraser make some headway and manage to connect the victim to a South American drugs racket.

A man is discovered tortured and executed on remote wasteland, and the team investigate, discovering that the victim was a hit-man. Soon their enquiries lead them to a local entrepreneur who they believe may have criminal connections. But they also have other concerns as Burke is caught in the wrong place at the wrong time, and Chief Superintendent Henson has marked him as a troublemaker, and she is determined to make sure his days in the police are numbered.

When a college principal is crushed to death in a lift, the preliminary investigation into his death discovers that the lift mechanism was deliberately sabotaged, and the finger of suspicion points to the dead man's wife, who may have avenged herself over his adultery. But DI Ross believes that the deputy principal has a hand in the murder, and sets out to prove the man's guilt.

The body of a private investigator is discovered at the bottom of a local quarry. After learning from the victim's fiancee that he was working on the case of a missing woman, and had claimed to have found her, the team become convinced his investigation is the key to solving the murder.

A campaigner against domestic violence is murdered and the prime suspect is an apparently reformed man whose violent behaviour once drove his ex-wife to almost kill him in self defence. Although the team is able to build a solid case against him, the investigation is put in jeopardy when Ross suffers a moment of madness.

When the decomposing body of a young woman is discovered in her bath, initial enquiries at her workplace uncover very little. Reid does not warm to her estate agent boss, while Fraser discovers that she was gifting a significant amount of her less-than-generous salary to charity, but why would that make her a murder target? Meanwhile, Ross learns that his estranged wife is planning to emigrate to Canada with his son, and realises he has a tough choice to make between his family and the job he loves.

Zbigniew Lisowski, a Polish migrant worker, is found shot at the building site where he worked as a security guard. Hours later, the body of hotel receptionist Kate Booth is discovered - with strikingly similar gunshot wounds. When investigations reveal that Kate - aka Kasia - was also Polish, the team have to consider whether a racially-motivated killer is at large.

When the body of a man is discovered in a garage with the engine of his car still running, it appears at first to be a simple case of suicide. The victim worked as a volunteer at a helpline centre dealing with potential suicide victims, and his wife is adamant her husband would never take his own life.