Alfie Mandeville doesn't know why he's been sent to Scarbrook House, a sanatorium where the children of Victorian Britain's upper class are hidden away. The only thing wrong with him is that he cannot sleep. But disturbing things are happening at Scarbrook - things that make Alfie wonder if he really is insane. A sleepwalker is found dead. A funeral is interrupted from beyond the grave. Worst of all, terrible creatures stalk the dorms at night, looking for a demon patient to drag back to hell, consuming anything that stands in their way. The only protection is to be asleep - but Alfie is wide awake...