FBI operative Mark Stevens is dispatched by his boss Lloyd Nolan to infiltrate a criminal gang. Stevens ingratiates himself with Richard Widmark, the gang's leader, then helps concoct a robbery that will deliver the criminals into the hands of the authorities. But there's an informant in the police department, who gets word back to Widmark. Aware that there's a stoolie in his gang, Widmark automatically assumes that his wife Barbara Lawrence is the guilty party, and beats her senseless. Eventually determining that Stevens is the "mole," Widmark methodically plans to kill Stevens during a holdup; by this time, however, the FBI is a step or so ahead of him. Remade in 1955 by Samuel Fuller as House of Bamboo.
by Hal Erickson synopsis