1966 brings Endeavour a fresh quartet of baffling mysteries set to test his brain and body to breaking point. Though offset by the possibility of love unlooked for, against a backdrop of growing change in Britain and the wider world, Endeavour must face a challenge that threatens to take from him all he holds dear... Family. Friends. Colleagues. The old order changeth... but not without a fight. To the death.
Returning from sick leave, Morse investigates a suspicious suicide, a missing girl, and the theft of a Trove (ancient artifacts). A beauty pageant and local by-election draw Morse into disagreement with Inspector Thursday and Superintendent Bright when he believes they are connected to the crimes despite the evidence. A missing notebook and a Freemasonry lodge hamper the investigation.
World Cup fever is gripping the country, as Argentina battle it out against England in the quarter finals. At an Oxford museum, some schoolgirls take a tour of the museum. In a closed-off enclave, Adrian Weiss, a specialist in heraldry and genealogy, is murdered, leading Morse to delve into the murders, 100 years previously, of a family who lived in the building the schoolgirls now occupy.
Bonfire Night is just around the corner and housewife Vivienne Haldane is found strangled with a silk stocking in her own home is the third death in a month. All the women were married, alone and their wedding rings missing. Tracing the stockings to the sole supplier, Burridges department store, and a number of suspects and for Inspector Thursday a face from the past he thought was dead leading to complications in his family life and with Morse.
A boy, with a brutal father, is reported missing from his home. The body of a journalist is found on a railway line and within days an escaped convict, with months of his sentence remaining, is found dead. The two men have connections with Blenheim Vale, a disused correctional facility for boys, soon to be redeveloped as a new police headquarters in a reorganization of the local forces. Thursday and Morse's investigation lead to a property developer and corruption in high places including missing police evidence in Morse's last three investigations.