When a phone with a brutal drowning recorded on it is handed in to MHU headquarters, the pressure is on for Annika and the team to track down the murderer.

The MHU are sent to Edinburgh to investigate the death of a recently released prisoner whose body is pulled out of the Forth River, imprisoned in a dog cage.

Annika reflects on Jekyll and Hyde as she and the team investigate a millionaire found dead in his own shark tank.

Annika reflects on 1984 when the team investigate the death of a man found in a block of ice on the Hebridean islands.

When Morgan starts working at a remote Scottish eco-resort, Annika's trip to visit her is interrupted when a local builder employed by the resort turns up dead in a nearby stream.

A brutal murder on Glasgow's canals hits close to home when the victim is identified as a former police officer.