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.
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.
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.
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.