Mrs. Peel is bequeathed an old house by an uncle Jack, whom she never knew existed. In the event, he did not exist. The house is a former lunatic asylum and it is all a ruse by a vengeful ex-employee of Mrs. Peel's to submit her to mind games which will drive her insane.

Economist James Broom is shot with an arrow by one of a group dressed as Robin Hood whilst on his way to meet a man opposed to his Utopian vision of a new Europe. The trail leads the Avengers to St. Bode's College, where anarchic students oppose traditional schools of thought. Could one of these have killed Broom? All is revealed at a fancy dress party where everyone is a character from the Robin Hood legend.

Eleven businessmen and counting have been mysteriously murdered, their affairs taken over by their able secretaries. The smell of perfume lingering over one of the dead bodies leads Mrs Peel to J.J. Hooter, who quickly becomes the next man to snuff it. With secretaries as their only clue, Steeds decides to hire one and Emma to take up the profession.

Two undercover agents are shot at Q.Q.F. Incorporated but one survives long enough to clue in Steed and Peel. So, Steed visits the Quite Quite Fantastic office (where fantasies are made to come true) while Emma looks into B. Bumble's honey shop. They soon surmise that someone is aiming for Prince Ali of Barabia, who is visiting London with his harem of 320 wives.