“The seal must not be broken. What’s inside must not get out.” *The 10th century A.D.* Fanatical Christians rebelling against the Pope dig deep into the Earth in a quest to find Hell. And for a thousand years, they kept on digging. *The present day.* A group of American college students stranded in England descend into an abandoned medieval mine, where they encounter a hellish nightmare world. Getting in was easy. Getting out will unleash Hell on Earth.