The Man Outside (1967)

Bill MacLean is a former CIA agent living in London. He had been fired when he stuck up for one of the men in his command who turned out to be branded a Russian defector. The embittered ex-agent combines forces with another operative to deliver a top Russian secret police official for a price. Before he can deliver the Russian, a trail of corpses and double crosses changes his plans. When his partner who concocted the scheme is murdered, MacLean returns the check to the CIA. They offer him his old job back, but the proud man refuses.