Doctor Who: The Mind of Evil (TV)

The Doctor and Jo visit Stangmoor Prison for a demonstration of the Keller Machine - a device claimed to be capable of extracting negative emotions from hardened criminals. The Doctor's scepticism seems valid when a prisoner called Barnham collapses whilst undergoing the treatment. The Brigadier is meanwhile in charge of security at a World Peace Conference, where documents go missing and the Chinese delegate dies in mysterious circumstances. Captain Yates is away on another mission, transporting a banned Thunderbolt missile across country to be destroyed. The Doctor joins the Brigadier at the conference and they foil an attempt by the Chinese delegate's aide, Captain Chin Lee, to kill the American delegate. Lee is under the hypnotic control of the Master - otherwise known as Professor Emil Keller.