Abstract: An improved double latch dead bolt lock operating mechanism wherein the dead bolt has a keyway engaged by a key for guiding the latching and unlatching movement of the dead bolt but allowing vertical movement of the dead bolt for accommodating any undesired engagement of the operating cam with an improper portion of the dead bolt. The dead bolt is resiliently urged vertically toward the operating cam to return the dead bolt to its normal vertical position after the cam to passes that improper portion of the dead bolt.