Control has come to suspect that there is a mole deep in the organization. By 1972, alone in this belief, he has ruled out all but his five senior lieutenants: Percy Alleline, Roy Bland, George Smiley, Toby Esterhase, and Haydon. To save his agent, Karla engineers the professional ruin of Control and Smiley whom he reckons to be the most likely to unmask Haydon. Karla is aware of Smiley's one personal weakness — his unreciprocated love for his wife Ann, who is a habitual adulteress — and orders Haydon to have an affair with her to cloud Smiley's judgment further. As Control is about to discover the truth, Karla lures him into ordering a doomed operation in Czechoslovakia to learn the identity of the mole from a (fake) Czech defector. Control picks Jim Prideaux for the operation and Haydon chooses to sacrifice his close friend to save himself. Prideaux is captured and reveals under duress the full extent of Control's knowledge of the mole to Karla before being repatriated to Britain and discharged from the Circus. Control is dismissed and dies soon afterwards, Smiley is forced into retirement, and Alleline becomes Chief. Haydon assumes control of London Station, in control of all foreign operations, effectively giving him unfettered access to intelligence worldwide.