This horror film is, pun inevitable and intended, pretty decent. A friend recommended I watch it late at night with as few lights on as possible to get the best effect, and I can see why.

It’s a simple enough tale – a group of female potholers find themselves in a perilous situation underground, and as they struggle to get back on course, come to realise that they may not be alone in the caves. The film’s got a good number of jolts in it, there’s some good dialogue, and the characters are all fairly well-written and acted.

My only gripe would be that though the film doesn’t outstay its welcome (the running time, according to the box, is 95 minutes), I found the supernatural threat element of it, coming so late in the film, was almost superfluous; there are some genuinely tense scenes of people in very claustrophobic situations, and they’re well acted and directed to the extent that when we start to get the idea there are creepy things in the darkened corners of the caves, it’s almost unnecessary, as the environment itself is threatening enough.

But it was worth a view, and if you do watch it at home, I’d echo the recommendation that you do so at night with little lighting, so as to emphasis the disorienting effect of events onscreen being illuminated solely by headtorches and emergency flares.