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.

Having found the body of the girl whose arm was found at the crash scene the team learn of an Albanian connection, while DCI Deacon continues to try and divide Sam and Leo. And there is no shortage of people who think they are responsible for the crash.

A dark tale of powerful emotions unravels when three members of the same family are brutally murdered, and Sam is surprised to encounter a face from her past. Meanwhile, Harry takes on a seemingly routine case but is beset by doubts.

Sam befriends a victim from the Irons family murder inquiry and makes a very disturbing family revelation, while Harry and Leo find their professional reputations under scrutiny.

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.