The team investigates the death of a radio DJ and a naval officer who were both killed live on air. Their job is made more difficult by the discovery of a number of different suspects.
While investigating a string of Alpha-related crimes, the team realise that the Alpha they are searching for is one of their own. Nina's past catches up with her. John opens up to Rachel.
A fisherman, trawling off the English coast, comes upon what appears to be a large fish in his net. But it turns out to be a dead body. The body is wearing shoes and a Rolex watch, but has no I.D. - is it murder or suicide?