One night, a figure in a bird costume breaks into the office of Simon Roberts, the owner of a publishing company, and slashes him to death.
An audio dictation made by Peter just before he died refers to an ongoing legal battle between the Roberts publishing company and Sir Lexius Cray, an acclaimed mountaineer who is one of their authors.
Peel returns to Cray’s country mansion at night to further investigate and discovers the assailant entering the grounds, but it is too late to save Tay-Ling from being murdered.
Based on evidence found by Tay-Ling’s body, Cray reveals that an inventor named Professor Poole had previously asked him to endorse a pair of boots that allowed the wearer to climb quickly up walls.
The manner and marks of the murders lead the two to consider how similar the assailant is to the ‘Winged Avenger’, the hero of a comic book that Peel found just by Tay-Ling’s body.
Poole reveals that the boots work using magnetic fields and that the only other pair was sold to an anonymous bidder from Winged Avenger Enterprises.
Steed returns to the offices and finds Julian’s dead body, He examines storyboards to see illustrations of Professor Poole in peril.
Stanton protests his innocence, and the two work out that Packer is the assailant, having produced his series of storyboards predicting Mrs Peel being murdered at Poole’s house.