Jack Brooks (Trevor Matthews) is an inconspicuous and unlucky plumber. He witnessed the horrific scene of his relatives being brutally murdered in his childhood, and he still has a shadow in his heart. Although he has a blonde girlfriend, he still has constant troubles. One day, Jack, who was confused, accidentally exposed the water pipe, and an old object reappeared in the world. Jack's night school professor Gordon (Robert Englund) found a beating black heart during the inspection. The heart then drilled into Professor Gordon's mouth. The controlled professor turned into a terrifying demon and began to kill the surrounding humans on a large scale. The situation was extremely urgent. Because of the accidental mistake that released such a terrible demon, Jack decided to eradicate the demon himself...