It's 1953, and Sidney Chambers (James Norton) is vicar of Grantchester, a village just outside Cambridge. Sidney's is a quiet life. Or at least, it has been - right up until the moment that murder comes his way. Pushed into the dangerous world of lies, betrayal and murder, Sidney quickly finds that his insight into the human condition, and the natural trust that he engenders in people, means that he excels in his new position as detective. Joining Sidney as he journeys into this dark world is the affable but world-weary Detective Inspector Geordie Keating (Robson Green).