Mission: Impossible (1966) : 7x12

Peter Cordel, a hitman and grandmaster chess player, has evaded capture - the IMF must bring him to justice and determine who in the Syndicate he works for. Using a hypnotic drug given by guest-agent Sandy, the IMF condition Cordel to blackout every time he is told ""When in doubt, take a pawn."" Then they set it up so it looks like he kills several people during his blackouts and have him awaken in a mental hospital where an IMF orderly stages an assault to make it look like Cordel's boss wants him dead, so Cordel tells Sandy to warn his boss to call off his hit men, and the IMF capture the man.