A boxer dies from brain injuries mid-bout. A new DSI takes over the team's investigations. Sam and Wyn bury their mother.

Sam discovers why Kevin entered a bare knuckle fight, as well as uncovering evidence of more foul play in the boxing circuit.

Stuart Evans is in the advanced stages of Aids when he dies, and his body is donated to science. However a routine toxicology test reveals foul play was at work.

The police make an arrest, but do they have the right suspect? Sam pursues her own line of investigation.

The murder of a married woman who was having an affair seems straightforward. Friction develops between Dr Ryan and the police when the evidence complicates their case.

The murderer makes a direct threat against Sam's life after she uncovers the evidence needed to identify them.

Sam's pursuit of her own theories leads her into dangerous places, both personally and professionally.