Professor Leo Dalton and Dr Harry Cunningham join Sam Ryan in the investigation of a massive traffic accident in which not everything is as it seems.

Sam, Leo and Harry are at odds with the police investigators when a covert operation is exposed. But has Sam overstepped the mark this time?

Murder is suspected when the body of a missing person is found hidden within a derelict factory, seven years since he was last seen alive.

As Sam searches for the killer of Marcus Saul, Harry finds himself involved in the tragic death of a student from the medical faculty.

The murder of a probation officer leads the team to the doorstep of a police cadet college, as they quickly establish a link to a similar murder just months before.

As the police investigate the possibility of a copycat killer among the students, a friend from the college pressures Sam to put loyalty above the truth as the case unfolds.

The bodies of two young men are discovered, partially exposed, following a landslide on the coast of Northern Ireland.

The case takes an interesting turn when the bodies are identified as brothers who disappeared after a police questioning during the Troubles.

Suspicious symptoms afflicting a group of children on the coast may be linked to the death of a local man.

Leo hunts for the source of the children's symptoms before any more fatalities occur. Meanwhile Harry discovers the truth behind Nick Garner's death.

When his wife and teenaged daughter are involved in a hit-and-run car crash, Leo begins a painful journey back to his native Sheffield.

As the police infiltrate a gang of identity thieves, Leo faces a choice between justice and revenge.

The team is called to a drive-by shooting outside a London nightclub. They arrive to a scene of carnage with several people dead, or dying.

The man behind the bloodshed pits both factions against one another and the team are in a race against time.

A paranoid schizophrenic goes on a violent frenzy in a busy high street. When a young man from the same care home commits suicide, Nikki is convinced there is a connection.

Harry discovers Nazim's death may not have been suicide. Is Dr Sanders the culprit? Meanwhile Leo investigates the murder of a bank manager.

Lively and diverse conversation. Mariella Frostrup meets children's author Allan Ahlberg, singer Kiki Dee, writer Nigel McCrery and artist Julie Brook. Show more

The police bring in the team when a family is attacked in their own home, leaving the only survivors in critical condition.

A new murder turns DCI Ashton's suspicions toward the victim's family and friends, whilst Harry investigates a death that may be linked to the Irons family.

Crime drama. When the team receive information that a club fire in 1996 that killed criminal Mark Johnson was a targeted attack, they re-open the investigation. Show more