Smiley's People, by John le Carre. New York: Bantam Books Inc. $3.50.

From the discovery of a former Red Army general shot dead on Hampstead Heath, to a Berlin reminiscent of the cold war, to the striking denouement, Smiley and his people are superb entertainers.

Smiley, the British spook, is restrained by doubt and a sense of decency as he methodically plots the capture of Soviet spymaster Karla. Even as he lays the trap, something in Smiley hopes it will snap shut empty.