A young woman who is a Speleologist teams up to explore an extremely deep cavern with a Geophysicist who believes that the earth is hollow and the Underworld is accessible through caves. Once sealed by Aboriginals, the pair soon regrets reopening the cave.

When a thirteen-year-old boy sheds his goody two shoes reputation for a day and skips school to explore Manchester with his friend, he doesn't expect to find himself in an underground cave system full of monsters, fighting to survive.

Two designers visit a historic English hotel with an attached maze, looking to propose a redesign of the property. As the maze entices them in mysterious manners, they come to uncover the dark history that continues to live on within its hedges.

After his twin brother's disappearance, Doug has become haunted by childhood memories and fruitlessly determined to understand where Danny went.

When a boy is lost in the darkness of a mine, a man resolves to confront his own worst nightmares.

An archaeologist finds an ancient funeral cave and intact skulls containing jars of bone marrow. When she studies one of the jars back at the lab, she accidentally exposes herself to its contents and experiences a strange transformation.

When a father's child is swallowed by a sinkhole, his quest for answers leads him into the dark secrets of an abandoned mine and a 1920's corporate cover-up.

British schoolteacher Paul once lived a quite life alongside his girlfriend, Anya. After the bomb, he's become the leader of a terrified group of survivors with only one place left to flee from the radiation - an abandoned system of mines.

Three friends in a magical world descend a staircase into the abyss at the edge of the world and encounter forces they can't control.

A woman notices a decrepit house moving closer to hers and decides to investigate it with her friends.