DVD, region 1, widescreen (2.40:1) presentation; Dolby Digital 5.1 surround, Dolby Digital stereo.

English or dubbed French dialogue, English or French subtitles; closed-captioned.

Title from container.

Cole Hauser, Morris Chestnut, Eddie Cibrian, Rick Ravanello, Marcel Iures, Kieran Darcy-Smith, Daniel Dae Kim, Lena Headey, Piper Perabo, Vlad Radescu.

Director of photography, Ross Emery ; editor, Brian Berdan ; music, Reinhold Heil, Johnny Klimek ; costume designer, Wendy Partridge ; production designer, Pier Luigi Basile.

Originally released as a motion picture in 2005.

MPAA rating: PG-13; for intense creature violence.

While on a dig in a Romanian forest, a group of scientists make a startling find. Dating back to the 13th century, they find a huge abbey, which was built over the entrance to a massive network of subterranean caves. Eager to learn what lies within the caves, the scientists discover to their peril that a large part of the cave system is under water. The scientists hire a team of American spelunkers who are trained in exploring underwater caves. The team is led by brothers Jack and Tyler. Armed with new high-tech SCUBA gear, Jack, Tyler, and the rest of their crew dive in to investigate the caves. A mishap traps them in a cavern beneath the surface, and they soon discover they are not alone.

Special features: Filmmaker commentary; "Designing evolution" commentary; "Into the crew" commentary.