Operation Witchcraft: the Circus's trusted poisoned source
Percy Alleline, Bill Haydon, Roy Bland and Toby Esterhase ran 'Merlin', a supposed Soviet source whose high-grade reports ('Witchcraft') won them Whitehall's praise and renewed American intelligence sharing. The channel's real purpose was to give Haydon, the mole codenamed Gerald, protected access to a Soviet officer, Polyakov, so he could pass British and American secrets. Control, the Circus's former chief, suspected a mole and sent Jim Prideaux to Czechoslovakia in Operation Testify to learn the mole's identity. The operation was betrayed: Prideaux was shot and captured, Control was forced out, and the men he suspected took over the Circus.
