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?