When a newly-qualified doctor is found tortured and mutilated in a vacant warehouse, the team discover connections with a drug-trafficking case.
When shipworkers' union leader Will Ramsay is shot dead in the middle of a labour dispute, corporate killing seems the most likely cause. But the real motivations lie much closer to home.
When Iranian refugee Farid Mamood is burned to death, it initially appears that a racially motivated murder has occurred. But Burke is not so sure.
When three children and their father are found dead in a tenement flat, what initially appears to be an open and shut case becomes something altogether more sinister.
The murder of a boxer leads the team into a murky world of cage fighting, illegal gambling and lap dancing.
Newly promoted DI Reid leads the murder investigation when a busker is stabbed to death in the city centre, but as the case progresses, Ross's life begins to unravel.