The loveably quirky Father Brown returns for a fourth series in the sleepy Cotswold village of Kembleford. He is aided by Mrs. McCarthy, Lady Felicia Montague and Sid Carter. A missing man returns just as his wife is about to remarry. When he is found dead, suspicion falls on those closest to him. Sid's romance with a brewer's daughter gets complicated when he learns she is married and is also her alibi for her father's murder.