The Cham-Cham

"The Cham-Cham" is the 25th episode of Thunderbirds, a British 1960s Supermarionation television series co-created by Gerry and Sylvia Anderson. One of the final instalments of series one, it first aired on 24 March 1966 on ATV Midlands. Alan Pattillo both wrote and directed the episode, which opens with a United States Air Force aircraft being shot down during the radio transmission of a popular instrumental music track. International Rescue suspects sabotage, and Lady Penelope, Tin-Tin and Parker are dispatched to investigate the band's current tour venue — a hotel in the Swiss Alps. There, it is discovered that the attacks are being co-ordinated with the aid of a "Cham-Cham", an advanced computer sensitive to microtones and ultrasonic harmonics. Filmed in late 1965, "The Cham-Cham" inspired innovation in AP Films' use of puppet characters; towards the end of the episode, the Penelope character performs a carefully choreographed cabaret dance, despite of the difficulties inherent in producing movement from the marionettes. Additionally, the episode marks the first occasion in any Supermarionation series that characters are seen skiing.