Sanctum

You can imagine the concept meeting. "Let's make a cave movie, they do good business!"

"No, let's make a climbing movie, Danny Boyle just did one so it must be hot!"

"Cave movie!"

"Climb movie!"

Ad infinitum

Until one compromising soul slaps his knee and says: "Y'know what, guys, let's do both!"

It's probably not as simple as that but, whatever the genesis of the project, there is no denying it is an amalgam of those two action disaster staples, so why it has been named Sanctum - a name dripping with the suggestion of horror - is anyone's guess. There are one or two grisly moments for sure, but this is scariness au naturelle, where the greatest horror comes from moments of intended 'deep' emotion, which ring as hollow as the cave system in which they are set.

The setting is Papua New Guinea - where actors plucked from a box marked 'native central casting' sit around in huts and a soundtrack aiming for National Geographic encourages you to get in touch with your inner Papua New Guinean or at the very least shore up the idea that this is "the last primeval wilderness".

Thousands of feet down, at the bottom of a cave named Esa'ala, hardbitten Aussie caver Frank (Richard Roxburgh) is trying to find the route this unexplored cave system takes to the sea along with his trusty crew George (Dan Wylie) and Jude (Allison Cratchley). It's a pursuit that brings him into almost constant conflict with his son Josh (Rhys Wakefield), who has been carted along on his dad's expeditions for years. Josh is about to join the cave party, along with Frank's backer Carl (Ioan Gruffudd) and his girlfriend Victoria (Alice Parkinson).

When rain starts to fall topside and the communications fail, it seems the only way out is down... but can any of them make it out alive?

It's testimony to the acting of Roxborough that we care even vaguely about their plight. Playing against his usual type, he is surprisingly convincing as the rugged, gruff Frank. Less successful is Wakefield, who was presumably cast for his floppy hair and ability to make his muscles bulge when climbing, rather than his acting talents.

Shot in 3D - and with James Cameron's Avatar rubber-stamping to boot - some of the rainforest and cave set ups are quite beautiful and the 'depth' does add something to the experience of claustrophobia in the caves. That said, there are plenty of times where the 3D feels, at best, redundant, and, at worst, distracts from the gentler scenes. Despite its high-level of contrivance and low level of emotion, Sanctum does at least succeed in its disaster set pieces but the inexperienced scriptwriting from Andrew Garvin (on whose experience this film is incredibly loosely based) and John Garvin shows in their desire to amp up the father/son dynamic even though it ruins the tension. Visually worth a look but lacking real depth.