Hooper, a secret agent has been shot by a man and a woman. His body is put on stilts meant to draw Steed to a special store. There is a certain dr. Krelmar who invented a machine which can switch the soul of a person into an other body and vice-versa. Steeds mind will be changed into the body of a spie of the enemy and later Emma Peel will be drawed by Steed, who isn't Steed anymore and she undergoes the same lot as Steed. So now both spies, who's minds are in the bodies of Steed and Emma, can infiltrate unlimited and they can eliminate half the network.