The Mysterons (voiced by Donald Gray) announce that they intend to destroy London. Aided by Captain Black, they use their powers to seize control of a transporter truck carrying a nuclear device through the city. The transporter and its driver, Macey, are sealed inside Park View, an underground car park. Macey, who was knocked out during the hijack, wakes up not knowing where he is. Turning on his radio to hear Big Ben strike midnight, he is surprised to hear 13 chimes instead of 12. The Mysterons start the nuclear device's 12-hour detonation countdown then knock Macey out for a second time and dump him in a side street.