Sam comes under intense scrutiny during an official inquiry into the deaths of two brothers while they were in prison. Her findings are soon challenged by her colleague, Leo Dalton, who is brought in to perform a second autopsy. Meanwhile, a series of murders that are taking place cast suspicion on a recently released ex-convict. He served years in prison after being convicted of killing his wife; the evidence against him was given by Sam during one of her very first cases. During his time in prison, however, he continued to deny his guilt. Sam begins to believe that someone is stalking her, while the police have trouble locating the ex-convict.

Sam and Leo, colleague Pathologists, are on opposing sides of a high-profile court case.

Whilst cage-fighting Jack takes on young Dean Fallon, drug dealer and son of career criminal Terry Fallon. When policeman Sam Honeywell's corpse is discovered in his burnt out car Dean is the main suspect after Honeywell had arrested him but is released for lack of evidence. Sam's colleague Carl Parry is then arrested when it is made known that Carl's wife Kate was having an affair with the dead man. After Dean has fallen out with his friend Jason Simons over Dean's girlfriend Tess Hughes Tess finds drugs hidden in her father Stan's garage, which she takes to Jason. Soon afterwards he too is killed.

Following Simons' death he is revealed to have been an undercover policeman infiltrating the Fallons' drug dealing empire. Tess questions her father and is shocked to learn that he is part of the gang before Stan gets a visit from Fallon's lawyer telling him to say nothing. There will be another death and a shoot-out before the killer is finally exposed.

A secret from his father propels Jack to Belfast. Meanwhile, Simone and Nikki investigate the mystery of a burned body. As familial secrets come to the surface, Jack faces tragedy head on.