Series 4

Detectives investigate the murder of a 17-year-old boy and gather evidence against a human trafficking gang, as public trust in the Met reaches a record low.

Detectives search for a missing young woman. After discovering CCTV footage of her going into a storage container with a man but never emerging, they fear she has been murdered.

Detectives investigate the murder of a homeless man who has been beaten to death in a London park and the rape of a young woman by a stranger on the street.

Detectives investigate the fatal stabbing of a motorcycle stuntman on a music video shoot. A manhunt team searches for a suspect on the run, accused of raping a 12-year-old girl.

An elderly couple are burgled and attacked in their home. The police call in the Flying Squad, an elite unit of covert officers who launch an operation to catch the perpetrators

Detectives investigate a series of sexual assaults and the mugging of an elderly woman. Contains some strong language and upsetting scene.