The vicarage family and the Keatings are on a much needed summer break at Merries Holiday Camp when the camp's owner is found dead in suspicious circumstances.

Will and Geordie negotiate a complex family dispute that may have something to do with the murder of the head of a local adoption agency; a sinister letter arrives for Leonard.

Will and Geordie are drawn into the cut-and-thrust world of local politics when the death of Councilor Derek McArthur prompts an election in Grantchester.

An otherwise quiet nightshift is disrupted when a group of young American airmen are arrested for trespassing at the local quarry and brought to the station.

As the day of Leonard's trial dawns, Will and Geordie are called upon to investigate an audacious robbery from a bank security van in Cambridge, which has had tragic repercussions.

When Leonard's cell mate Joe Davies is accused of murdering another inmate, he asks Will and Geordie for their help, but the brutal prison stirs up bad memories for Geordie.

When a successful music producer is murdered, Geordie finds himself implicated in the investigation, and forced to consider whether his army buddy Johnny could be the killer.