Season 9, Episode 5:
When the body of missing computer expert Martin Longthorn turns up in the morgue of a teaching hospital under a false name and address, the UCOS team find themselves drawn into the unfamiliar world of online hacktivists. Martin worked for the Metropolitan Police and his disappearance caused concern at the time. Why was his body hidden - and by whom? Meanwhile, Lane finds it difficult to accept McAndrew as the new UCOS team member and Esther is forced to intervene.
A motley crew of retired police officers re-opens troublesome cases that were never laid to rest.