Paul Beresford, the brother of Clement Armstrong, the creator of the Cybernauts, blames Steed and Mrs. Peel for his brother's death at the cold hands of his own creations. Aided by Armstrong's assistant Benson, he abducts several scientists who are blackmailed into producing a new batch of Cybernauts. Whilst he is the perfect gentleman towards Mrs. Peel, his aim is to turn her and Steed into human robots.
Sir Andrew Boyd, the British delegate at a European peace conference has a dream in which he is run over and killed by a car. The dream comes true. The Avengers are charged with the safety of his successor, Lord Melford. He too is beginning to have bad dreams, involving a sinister man who turns out to be a member of the Eastern bloc. There is a plot afoot to derail the conference and Steed and Mrs. Peel intend to foil it.
The Avengers go to the dogs as their only lead when $50,000 of stolen diamonds is found in a dead man's stomach. Mismatched Borzoi hairs lead Steed and Emma to a pet cemetery where they take the bite out of the villain's bark.
The hunt for a murdered courier's despatch leads Steed and Emma to a deadly car race with a "shocking" surprise at the finish line. It takes The Avengers to flag down the murderers and apply the brakes to their plans.
A scientist is killed by having been hurled through and embedded in a wall. This is the latest death of a person engaged in the government's Project 90, whose documents can also not be found. When the Avengers investigate they discover a bizarre means of murder whereby the killer can carry an electrical charge to the victim without being electrocuted themselves.
When Mrs. Peel's friend Major Croft goes missing she traces him to the picture postcard village of Little Storping. Unfortunately the entire population are assassins for hire who lure their victims to the village, kill them and then claim that they have never been there. Croft has been killed, along with his valet to prevent them from exposing the sinister secret and Mrs. Peel is next on the hit list unless Steed can save her. Fortunately, she manages to put in a phone call to her 'husband.'
A car carrying two Ministry officials, enroute to investigate the budget overruns on Professor Rushton's latest project, vanishes under escort. Steed goes to investigate, and discovers the hard way where the money has gone; to build a device capable of shrinking anything to a fraction of its normal size. While Rushton has great science- and industry-oriented plans for the device, his assistant Chivers has plans of his own... to make a profit, and dispose of anyone in his way. Steed, inches tall, manages to telephone Emma with a warning, but she is captured by a ...