Edmond O'Brien is a telephone repairman with a good ear for opportunity. It knocks at a bookie joint, where two businessmen harness his technical acumen toward a wire service connecting the racing results of all the West Coast tracks. With this entré into the mob, O'Brien proceeds with a ruthless brand of ambition, eventually taking over the operation and the boss's wife (Joanne Dru) in one murderous swoop. His demise comes in a furious climax at Hoover Dam. This tight-lipped syndicate exposé was supposedly shot under police guard so as to protect the film crew from underworld threats. But the mob had little to fear; in the end, in the smiling person of Otto Kruger, the syndicate remains fully in control, having lost nothing but one lineman whose dime was up.