It's 1955 and Sidney Chambers, the vicar of the small Cambridgeshire village of Grantchester, is once again aiding the investigations of his best friend, Detective Inspector Geordie Keating. Amidst the crimes of passion, murderous plots, and unexpected tragedies, Sidney has always had the stability of his role in the church to fall back on. But now, that stability is tested as the love he feels for his long-time sweetheart Amanda puts him at odds with the very institution he serves. In this personal crisis, will he finally be forced to choose between duty and love? The return of Reverend Sidney Chambers and Inspector Geordie Keating to solve a third season's worth of crimes in their small village of Grantchester, just outside of Cambridge, England.