Sanctum

“The only way out is down.”

In the Esa-ala Caves of the South Pacific, master diver Frank (Richard Roxburgh) has spent months mapping the passages when a flash flood seals the only way out. Alister Grierson traps Frank, his 17-year-old son Josh (Rhys Wakefield) and the financier Carl (Ioan Gruffudd) with falling supplies and a flooded labyrinth to find a route through. Their lights shrink to small beams in the water, and the rope is the only line back.