《摩斯探长前传》第五季共6集，剧情以1968年为背景，于2018年2月在英国独立电视台播出。Ex-boxer Joey Sikes is killed on the night of a failed theft of a Faberge egg from the Oxford college where it is to be auctioned. Next day lecturer Robin Grey is also murdered and the link is prostitute and artists' model Eve Thorne, who was seen with both men. When the egg is stolen suspicion falls on another of Eve's clients, latest victim Simon Lake and Morse discovers that Lake and Grey belonged to an elite club, involved in a scam regarding the egg. In establishing whether the murders were linked to the club or the egg Morse, now a detective sergeant, must cope with a lazy new constable and the reappearance of Joan Thursday.