After a severed hand is discovered, Cribb travels down to the seaside town of Brighton to discover the victim's identity, with the assistance of an eccentric holiday-maker with a tale of a missing woman.

A popular campaign is being waged to prevent the sale of Jumbo, London Zoo's most popular attraction to America. When the elderly animal-lover organising the protests is murdered, Cribb considers the various motives for killing her.

Jowett is very excited by the upcoming Golden Jubilee celebrations and is jealous when Cribb is selected by the Royal Household for a special mission—to investigate the background of the new nanny being selected for the Queen's granddaughter.

Cribb and Thackeray investigate the apparent suicide of a retired colonel, a member of a village choir. The detectives soon deduce that the Colonel's death was murder but their questions are met with a wall of silence from the locals.

Jowett returns to his old school for a small reunion. His suspicions are raised by an appeal for funds by an ex-classmate, who is subsequently murdered.

Cribb goes undercover to infiltrate the Irish Republican Brotherhood, who are planning a major bombing.