

Willis-Sopwoth, a top pharmaceutical firm, is being drained by cheap imitations of its products in foreign markets. The death of a member of staff while investigating the fraud brings Steed and Cathy face to face with a deadly artist and a plot to poison children.
Thanks to the clever briefing of the Lakin brothers a man charged with treason is found not guilty. Mrs Gale believes that Steed is implicated, and contacts the newspapers. Steed threatens her: either withdraw her allegations or pay the consequences. Soon Steed is on trial for Gale's murder.