ABC Weekend Television, who commissioned the show for ITV, broadcast it in its own regions three days later on Saturday 8 April.
Kanwitch, a crime boss looking for assassins, analyses the performances of men and women trained by Jessel, who boasts of the prowess of his work.
John Steed receives an invitation from Sir George Robertson, a famed explorer, to attend a fancy dress party he is hosting on an aeroplane.
When Steed boards the following day, he is greeted by his fellow guests - fencing school owner Max Hardy, bullfighter Joe Smith, game hunter Jason Wade, marksman Hana Wilde, strongman Freddy Richards and controversial ex-military officer Major Mark Dayton.
Whilst awaiting their arrival, Steed theorises that each guest has been chosen for their prowess in a particular field of armed or unarmed combat.
Joe becomes the second victim when he is impaled with a pitchfork after avoiding a falling wagon, and Max is fatally stabbed after losing a fencing duel with the assailant.
Hana and Mark soon find Jason dead from a tiger trap, leading them to conclude Steed is the killer.