Part of the schadenfreude fun of tacky Hollywood horror films is watching vapid American teenagers getting killed by supernatural foes. This British version kindly offers the same sort of dirty thrill, but with posh kids at a made-up public school being menaced by the murdered spectres of 17th-century students hell-bent on revenge, or something like that. The budget clearly didn’t stretch far enough to pay up for convincing gore makeup, and the LED-light eyes of the ghouls wouldn’t frighten a skittish squirrel, but as a genre exercise it’s merely underachieving, not outright atrocious. Some of the teen cast should think about alternative careers while they’re still young, but others – including Morgane Polanski (Roman Polanski and Emmanuelle Seigner’s daughter), and Marcus Griffiths as a cocky jock – put their backs into the mucky work and get the job done.