Gene and the rest of CID are feeling the pressure to stop a series of politically motivated arson attacks in the lead up to the 1983 General Election, after a military compound and a polling station are set alight. DCI Jim Keats announces his plans to monitor the way Hunt and his team work while trying to turn each member of of the team against Gene. Elsewhere, Alex continues to mount her investigation into what really happened to Sam Tyler in 1980 and is struggling to work out why she is being haunted by the young police officer.