The owner of a stamp shop is murdered when excitedly talking on the phone to a contact about the rare Mauritius Penny that has turned up on a list. Cathy Gale applies for a job in the shop, and she and Steed witness another murder in an auction room.

Michael Dyter, the newly elected MP for South-East Anglia is shot shortly after making his acceptance speech in which he had threatened to expose a major scandal involving the government. Steed knows that the subject of this was the recent theft of a nuclear warhead near London. So was Dyter killed to keep him quiet, and if so, by whom?

The accidental death of a ventriloquist reveals that he had been carrying a fortune in gems inside his stomach. Steed stoops to blackmail and Emma goes shopping for ties in the search through the business community for a rich Borzoi.