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.

Reconociendo el poder de su simio gigante cautivo, el ejército crea su propia inteligencia artificial lista para la batalla, Mecha Ape. Pero su primera prueba sale mal, dejando a los militares sin otra opción que liberar al simio.