Two boys go into a cave then it floods and one dies

After a personal tragedy, Sarah joins her friends on a caving expedition in the Appalachian Mountains. But when a rockfall traps them deep underground, their adventure turns into a nightmare. As they search for a way out, the group discovers they are not alone—lurking in the darkness are savage, cave-dwelling creatures. With rising tension and dwindling trust, the women must fight to survive against both the predators and each other.

In a small tranquil community, a group of individuals must unravel the secrets behind a series of horrifying attacks by mysterious creatures that emerge from the depths of darkness.

After a group of biologists discovers a huge network of unexplored caves in Romania and, believing it to be an undisturbed eco-system that has produced a new species, they hire the best American team of underwater cave explorers in the world. While exploring deeper into the underwater caves, a rockslide blocks their exit, and they soon discover a larger carnivorous creature has added them to its food chain.

A medieval soldier, alone in a frozen woodland, tends to a gravely wounded comrade when he is approached by an old woman who offers to save him. But first, the soldier must complete a sinister task as payment for this deed.

Master diver Frank McGuire has explored the South Pacific's Esa-ala Caves for months. But when his exit is cut off in a flash flood, Frank's team—including 17-year-old son Josh and financier Carl Hurley are forced to radically alter plans. With dwindling supplies, the crew must navigate an underwater labyrinth to make it out.