John returns to the cellar, where his powers are negated. Stephen attempts to rescue John, but his stun gun has no effect on Robert, and he is forced to flee. Chris and two friends also mount an unsuccessful attempt. Chris later follows the mysterious boy, but is warned off by a policeman. However he manages to retrieve some books, including volume four of �The Decline and Fall of the Roman Empire�, which Robert has dropped. Taking them to the Lab, Chris shows Tim, who realises that the Roman Empire also broke into two factions: blue and green. Robert instructs his grandfather to tell the police that he has gone missing, then leaves with John. Attempting to help Elizabeth at the school, Chris is instead caught by the police, who charge him with Robert's disappearance, and take him to the shop to look for the boy. When they get to the cellar, all of the pictures have gone, as has John.
Aired: 25 Feb 1974