Several weeks ago the TARDIS landed in Masada, Judaea. The crew got caught in a skirmish with Roman soldiers, and the Doctor and Susan became separated from Barbara and Ian. The Doctor and Susan joined Flavius Silva's Roman camp, and Ian and an injured Barbara joined a band of Jewish zealots. Over the next few weeks, the Doctor became an advisor to Silva, and Ian, while Barbara lay unconscious, has befriended the leader of the zealots, Eleazar ben Jair. Meanwhile, the Doctor is at pains to convince Silva that he has two spies in the Masada camp and to persuade him to let the spies live.