The Daleks and the Cybermen form an alliance to kidnap the American Envoy and ruin a peace conference on Earth. The Doctor meets a new companion, a Frenchman called Jason. After they fail to stop the Cybermen taking the US Envoy from a nightclub, they are joined by a singer named Crystal who works there. After a trip to Altair Three and then the Bar Galactica, they meet Madame Delilah but are forced to flee along with a small furry creature called Zog.