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 murder 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 killer, 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...