A top-secret chemical formula has been stolen by STENCH (the Society for the Total Extinction of Non-Conforming Humans). Fearful of the formula falling into the wrong hands, the chief of the Secret Intelligence Service reluctantly sends the only agent he has left, the bumbling and silly Agent Desmond Simpkins (Kenneth Williams), and his three trainees—Agent Harold Crump (Bernard Cribbins), Agent Daphne Honeybutt (Barbara Windsor), and Agent Charlie Bind (Charles Hawtrey (actor born 1914))—to retrieve the formula.