A playboy imprisoned for a bank robbery he didn't commit gets involved with a convict who's determined to make a daring escape in this vintage crime thriller shot on location at San Quentin prison. Sentenced to a long stretch behind bars after being framed for a brazen bank heist, Johnny Gray finds himself sharing a cell with Cain - a man determined to win back his freedom even if it costs him his life. When Cain confides his escape plan to his new cell mate, Johnny agrees to participate. Meanwhile, new evidence clears Johnny of any wrongdoing, and he is granted a full pardon. But Johnny's experiences behind bars have left him a changed man, and he decides to become a guard at the penitentiary. Little does Johnny realize that Cain is still determined to break out at any cost, and he fully expects his old partner to follow through on his end of the plan.