Colony Three, written by Donald Jonson, directed by Don Chaffey, ITV, tx. 24/10/1964

UN agent John Drake infiltrates an East European school for spies to investigate the disappearance of 400 agents. En route, he meets two British citizens - Janet Wilson, who is hoping to meet her friend Alan Bayliss, and Randall. They arrive at Hamden New Town, a re-creation of an English town where foreign agents are trained to appear English. They are greeted by Richardson, who takes them to see Donovan, the director. Wilson learns that Bayliss died after wandering outside the town area; residents are not permitted to leave. When Drake expresses interest in interrogation techniques, Richardson, by way of demonstration, administers dangerous levels of electric shocks, until they are interrupted by Donovan.

Later, Drake discovers the room he shares with Randall is bugged. Randall accuses Drake of trying to get in with the management. Drake rigs up his typewriter as a camera and in the morning uses his new position in the Citizen's Advice Bureau to photograph agents. Meanwhile, Randall discovers a metal strip inside Drake's pencil. He confronts Drake, who accuses him of planting it.

At a reception, Randall discovers the host is a missing Foreign Office employee, and fights with an agent. Later, during an argument in their room, Drake discovers Randall is planning to leave Hamden. Drake transmits a signal to London to request his recall. Randall escapes and, fearing for his safety, Drake gives chase. The two are re-captured. Randall attempts to convince Donovan that Drake is an enemy agent.

Drake's release is authorised by Donovan's superiors, arousing the director's suspicions. Donovan surmises Drake is working for London or Washington. Donovan agrees to release Drake, ordering Richardson to ensure that he does not arrive at his destination. As Drake boards the bus, Wilson sneaks a letter into Drake's pocket. Richardson announces that he is being sent on his first assignment and boards the bus with Drake. Later, aboard a train, Richardson asks for Wilson's letter and rips it up, asserting that once people enter Colony Three, they cease to exist. In his train bathroom, Drake fashions a weapon from a soap dispenser and a bag. As he leaves the compartment, Richardson comes from behind wielding an axe. Drake dodges the axe and in the ensuing fight Richardson plunges from the train.

Back in London, Drake asks his Chief if anything can be done about Wilson, but is told that no record can be found of her.