A group of experienced cave explorers in Papua New Guinea get themselves trapped underground when a cyclone above ground begins to flood their passageways. It then becomes a desperate race against time to find an escape route before they are completely cut off from the outside world for ever.
Based on true events, the film is claustrophobic, dramatic and unpredictable. Some genuinely good sequences which evoke memories of "The Descent".
Definitely worth a look.
Originally shot in 3-D.