The lab is invaded by the SIS, who inform the Tomorrow People that Pavla, a telepathic girl working for the KGB, has gone missing in London. The Tomorrow People must try to protect her from the intelligence agencies of two countries.
Mike manages to escape from the KGB but Pavla is taken back to the embassy as a prisoner. John and Mike attempt a rescue but to their surprise Pavla refuses to go with them.
The Tomorrow People take a holiday on the planet Galia, but when they come across two runaway slave boys, it becomes clear more goes on than they were first aware.
Timus arrives on Galia and confirms he was aware of the Klepton enslaving the natives. Since the Federation will not agree to direct intervention, it is up to the Tomorrow People to free them.
A stranger, Jake, offers to manage Mike's band, but when Liz learns that he is the leader of a religious group called the Hearts of Sogguth, she begins to wonder what his motives are.
Jake sends John to kill Liz, but forcing a Tomorrow Person against his nature breaks his possession. John and Liz realise that if Mike plays Sogguth's drum on live television, Sogguth (Satan) will be released into the world.