Five go mental in a monitored cabin. The assembled assortment – Chris Hemsworth, Fran Kranz, Jesse Williams, Anna Hutchison, Kristen Connolly – think they’re off the grid for the weekend. In fact, every move they make is being manipulated. For unfeasibly hellish reasons, it turns out. Clever but not scary, this is a gore-fest as cute as Cube and as digitally overloaded as Th13teen Ghosts. It understands the clichéd mechanics of horror movies but apparently – unlike Wes Craven’s Scream – not what makes them frightening in the first place: engagement with characters, not ciphers. As the title suggests, there’s a fairy tale quality to the conceit. But there’s precious little context. Taking place in a vacuum, it’s all concept.