The Puppeteer, a convicted murderer on death row, has always maintained his innocence, claiming that it was an evil force that controlled his body as he slaughtered his victims.

Recognizing the power of its captive giant Ape, the military makes its own battle-ready A.I., Mecha Ape. But its first test goes horribly wrong, leaving the military no choice but to release the imprisoned giant ape to stop the robot.