Neil Marshall followed up the success of Dog Soldiers with this equally scary, compelling horror story, released in 2005. Six women arrange a caving expedition to help one of them, Sarah (Shauna MacDonald) overcome a personal tragedy. But once the women are down in the dark, they find themselves in an uncharted system. Panic sets in when they realise that they are they not alone. Worse their "companions" aren't necessarily human...
Unsettling, claustrophobic and nerve-jangling, this is not one to be watched alone or in a small, dark room.