It's the week before Christmas 1954, and the forecast is for snow in the beautiful Cambridge village of Grantchester. For vicar Sidney Chambers, this is the busiest time of the year and he is rushed off his feet with festive duties. Which is useful, as it means he doesn't have time to think about his beloved Amanda, estranged from her husband and heavily pregnant, who has taken up residence nearby with her Aunt CeCe. Sidney loves her - but whether she's married or divorced, there is no way he can be with her. Meanwhile curate Leonard Finch is embarking on an ambitious production of the nativity with the local children, and Detective Inspector Geordie Keating is grumpy at the festive spirit - all of which leaves Sidney happy to bury himself in his pastoral work. Which is when a weeping bride reports the disappearance of her husband-to-be, and Sidney and Geordie find themselves drawn into picking through the murky motives of a winter wedding. When the would-be groom turns up dead with the wedding rings lodged in his mouth, Geordie is horrified - it has all the hallmarks of an unsolved hug from nine years before. Geordie's prime suspect back then was local toyshop owner Albert Tannen. While nothing was ever proved, creepy tales and gossip have turned his once-lively business - and personality - into a twisted shadow of its former self. Geordie and Sidney must hunt for the hugger, and hope to bring justice to two women mourning for their lost loves at Christmas time. But as the dangers grow, snow starts to fall... and waters break...
It is 1954 and just outside Grantchester, Sidney Chambers is enjoying a picnic with his best friend, DI Geordie Keating, Geordie's family and his shy curate Leonard Finch. Walking home, DC Phil Wilkinson arrests Sidney accusing him of sexual assault.
Geordie and Cathy are on a mission to find Sidney a girlfriend - but nobody seems to be good enough for the choosy vicar. Geordie's plans are further thwarted when Sidney's old flame, Amanda Hopkins arrives in Grantchester while Guy is away on business.
After thoroughly modern Margaret's visits to the vicarage start leaving Mrs Maguire's nose out of joint, Sidney is hoping for a distraction - which arrives in the unexpected form of a young man sat alone in the church and covered in blood.
As the trial of local teen Gary Bell approaches, Sidney and Geordie find themselves at loggerheads regarding his guilt - not even building a go-kart together can get them to see eye to eye. Sidney's mind is taken off these matters when he finds the anxious Reggie Lawson at the graveside of his dead wife, Anna. Convinced that she still haunts his home and stable yards following her suicide he implores Sidney to come to his estate, Kingsbrook and perform an exorcism for him.
Sidney is Gary Bell's only friend left as he waits for news about whether he will be offered a reprieve. Sidney decides he will stand by his side even if certain members of the village complain.
Mrs Maguire and Leonard are both very worried about Sidney, it is left to them to try and come up with a way to help their friend before it is too late. Geordie and Amanda are seemingly unwilling to help, and with an attempt to remove Sidney from the vicarage gaining strength, things are not looking good.