Josh McGuire (Rhys Wakefield), son of renowned cave-diver Frank (Richard Roxburgh), reluctantly leads a bank-roller and his girlfriend down to the bottom of a cave where his father eagerly waits to show his latest findings in an area called Devil's Restriction. Upon entering the deep camp disaster strikes as Frank is blamed for being unable to save colleague Judes (Allison Cratchley) from drowning which opens up the fragile relationship with his son.
A storm brings further tragedy as the cave begins to flood leaving the expedition with little option but to swim down into uncharted caves after finding their way back is blocked by torrential waves.
There have been a great number of films that explore firstly the depths of water, and secondly the ability of a group of relatively unknowns to pull together and escape their fate. The script is almost identical for each, bar the odd change; brief introduction as group meets, impending tragedy is announced, small warning is overlooked by the alpha of the group just before tragedy strikes, very few escape tragedy as story ends on hallowing note.
The reason that the "Tragedy" genre has continued to live on despite this is down to a simple, albeit grisly fact; people like to guess who dies when. Happily, if you can say that, Sanctum lives up to the disturbing marker lay down by its predecessors and, with a little James Cameron's Titanic magic thrown to keep the sets looking as real as ever, delivers it in a very aesthetically pleasing manner.
As with an film in the genre, the lack of protagonists means that the story focuses heavily on character development. This is a risk, which does partly pay off. The characters Frank and son Josh are a huge part of the story and is brilliantly acted by both Wakefield and Roxburgh who keep the movie ticking over as the pair struggle with their fragmented relationship. Outside of the couple though, there is very little other substance.
A decent enough movie, excelling in bringing back some quality to an otherwise badly over-used genre, with a shocking ending.