The team pieces together the mystery of a man found dead on the shore of the Thames, while the life of a disgruntled criminology professor begins to unravel. The team works on a suspected suicide, but the investigation raises more questions than it answers. Gabriel has an exciting new opportunity, both professionally and personally, and enlists Jack's help. When a disgruntled professor of criminology is passed over for promotion, events take a truly sinister turn and the interview panel begins to be targeted. Could a member of the Lyell be next?

The team investigate the body of a woman found in a flat after being dead for a year. As they seek to find out the truth of her identity and what happened to her, they must draw on all their forensic and pathology knowledge to solve the case. Even if the world had forgotten her, the Lyell are determined she must get justice.