A group of archaeologists, headed by Donald Pleasance, have entered the secret catacombs which have been sealed for centuries. In their ignorance and quest for the unknown, the archaeologists have broken the seal to the gates of hell, unleashing a terrible evil not seen on the face of the earth for nineteen thousand years. The heart of the evil lies in an unexplored catacomb into which the archaeologists lower a computerised camera. The air, odour and silence over in a menacing atmosphere as the camera scans the darkness, revealing a centuries old tomb. Donald Pleasance interprets the inscriptions of the tomb and realises the true horror of his find. He has a evoked an evil so terrifying that it could destroy mankind as we know it. There is only one solution, to seal the tomb. It's now a race against time and head-on clash with the powers of centuries long forgotten.