While hiking with his two young children, a man falls to his doom in a cavern called the Bottomless Well, leaving his son and daughter to race to save his life.

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

A teacher takes her students on a field trip to a tin mine. While underground, a haunting legend foreshadows a grotesque, karmic tragedy.

A team of female scientists excavate an ancient burial site located off of Lake Superior. Uncovering inhuman remains, they begin to question if the human bones were simply decorations for the tombs of something far more sinister.

A group of explorers take a traveler to tour a cave where ghosts sing songs forgotten by the living. Upon entering, they realize they underestimated the effect the songs have on the psyche.

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.

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.

When a group of boys happen upon a prehistoric cave in France while out hunting for rabbits, they must decide who is trustworthy enough to share their secret with.

Two men have been locked underground somewhere in Utah, Montana, or Idaho with instructions to wait for a monitor's signal then each turn a key in a lock simultaneously to fire a "bird" at an unknown target city. They also have guns and instructions to shoot the other if the other behaves strangely.