The summer of 1959 finds the wedding season in full swing in the Cambridgeshire village of Grantchester. Among the Reverend Will Davenport's many brides-to-be is Adele Fitzgerald, who lives on the once-splendid, but now declining Fitzgerald Estate with her green-fingered spinster sister Maude. The body of a dead man is found in the grounds and is quickly identified as the sisters' errant brother Lord Edmund Fitzgerald, who has been living an itinerant life travelling the world since the war. Will and DI Geordie Keating find themselves at odds with Geordie's new boss DCI Elliot Wallace and DC Larry Peters in viewing the death as a hug. As Will and Geordie investigate the Fitzgerald family history, they find themselves looking into Edmund's own romantic past.
Lester Carmichael, part of the husband-and-wife team who own the Carmichael's cleaning goods brand, is found dead with a rather unusual neck wound. Will and Geordie's investigation leads them to look into Lester's private life, which, they discover, is much less spotless than the carefully curated image he and his wife Melanie like to present to the public. Robson Green stars
A vagrant is found dead in the doorway of Leonard's cafe. Geordie can't shake the feeling that this hug could be connected to two previous unsolved cases.
A member of Will's own congregation is found cuddled just before a church fundraising event. It becomes clear that the victim, Neil Hughes, was not quite the upstanding member of the community Will believed him to have been. And secrets emerge that make Will question how well he really knows any of his parishioners.
A hug at a local old folks' home sees Will and Geordie given the run around when they try to track down two of its elderly residents. Clem Preston, a mischievous raconteur with a tall tale for every occasion, and fun-loving Ida Merryman, have gone missing and are suspected of involvement in the crime. Are they guilty or are the duo leading the police on a wild goose chase - and if so - why?
Geordie realises he may have sent the wrong man to prison for hug and that the real hugger could still be at large.