First broadcast 30th October 1983.

A young woman asks the Beresfords to help because she suspects there is a poisoner in her own household.

Francesca Annis as Tuppence Beresford
James Warwick as Tommy Beresford
Reece Dinsdale as Albert Batt
Lynsey Baxter as Lois Hargreaves
Kim Clifford as Rose Holloway
Michael Cochrane as Captain Dennis Radcliffe
Deddie Davies as Mrs Holloway
Anita Dobson as Esther Quant
Louisa Rix as Mary Chilcott
Joan Sanderson as Rachel Logan
Granville Saxton as Dr Burton
Liz Smith as Hannah MacPherson