With the TARDIS stuck at the bottom of a cliff, the First Doctor, Ian, Barbara and Vicki have installed themselves in an unoccupied Roman villa. As the Doctor and Ian recline, Barbara and Vicki walk to a nearby Roman village. They are spotted by two slave traders, Didius and Sevcheria. When they return to the villa the Doctor announces that he is off to Rome, some miles away, and will travel there with Vicki. Later that evening Barbara and Ian, now alone, are relaxing when the two slavers burst in upon them. They are overpowered and taken prisoner. Ian is sold to one slave owner, while Barbara is to be traded with another and sent to Rome.