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.
Elenco: Cole Hauser , Eddie Cibrian , Morris Chestnut , Lena Headey , Piper Perabo , Rick Ravanello , Daniel Dae Kim , Kieran Darcy-Smith , Marcel Iures , Vlad Radescu , Simon Kunz , David Kennedy , Alin Panc , Zoltan Butuc , Brian Steele .