Using massive piloted robots to combat the alien threat, earth's survivors take the fight to the invading alien force lurking in the depths of the Pacific Ocean. Nearly defenseless in the face of the relentless enemy, the forces of mankind have no choice but to turn to two unlikely heroes who now stand as earth's final hope against the mounting apocalypse.

An other-worldly story, set against the backdrop of Cold War era America circa 1962, where a mute janitor working at a lab falls in love with an amphibious man being held captive there and devises a plan to help him escape.