Skeletons keep turning up at a home in North London. The bones belong to three young woman killed more than 17 years earlier, when a family ran a bed-and-breakfast there.
North joins a team reopening an old case involving James McCready, convicted of murdering his partner. Citing new evidence, a barrister wants to overturn the conviction.
Undercover officer Jake Brown is a streetwise cop who has infiltrated Manchester's drug trade. When straitlaced DI Carl Harrington angles his way into Brown's undercover operation, the two are drawn into a dangerous showdown with a big drug supplier.
Personal and professional pressures mount in the McCready case when North uncovers irregularities involving Walker, who led the original investigation.
Teenager Cassie Booth vanishes in the midst of her newspaper delivery route. Walker's hopes of finding her alive fade when an anonymous tip leads to grisly clues.
After a prostitute's tortured, mutilated body turns up on a garbage heap, DS Michael Walker and DI Pat North know they face an exceptionally sadistic psychopath.
Patient and persistent, Deputy Chief Constable Stephen Blackton (David O'Hara) has earned his nickname, "Blackdog," as he is called in to re-open the investigation of the Lionel Cripps shooting.
Commander Blake's terminally ill sister moves in with her while Blake deals with the dangerous computer hacker who has threatened to kill more patients every 24 hours.
A young woman disappears from a nightclub, and a mental patient, Reginald Aitken (Nickolas Grace) escapes from a hospital. Hours later, the two are found together covered in her blood.
Newly promoted, Commander Clare Blake (Amanda Burton) vows no cover-ups. When a previously convicted killer, James Lampton (Hugh Bonneville) gets released on parole, Blake's judgement is put to the test.
Brian believes that someone else was in the room with him when he found his mother's body. Commander Blake is forced to take extreme action to find the truth and accept the repercussions. Will they find the abductor of DCI James' baby?
DS Michael Walker joins DI Pat North in investigation of a child's disappearance. They target Michael Dunn, an unemployed alcoholic who lives in the neighborhood.
Dutch DI Count Eric Van Hauten offers to help DCI Hedges with a new murder case. Commander Blake pledges to remain uninvolved, but will she be able to as the threat of more victims increases?