Four robbers knock off a bank in Kansas City with plans to split the money after the heat has cooled. The mastermind behind the job has arranged it so the crooks don't meet before the job, and wear masks during it, thus can't possibly identify each other. But each man has an ace, torn in half to create a unique mate, to match with the second half and confirm his identity when the time comes. It all sounds clever and foolproof, except the mastermind has framed someone for the robbery to throw police off their trail, and when this man is arrested but turned loose from police custody due to lack of evidence, he decides to track down the men who set him up.