John Ajvide Lindqvist 
I Am Behind You 

A supernatural superthriller from the author of Let the Right One In Molly wakes her mother to go to the toilet. The campsite is strangely blank. The toilet block has gone. Everything else has gone too. This is a place with no sun. No god.Just four families remain. Each has done something to bring them here – each denies they deserve it. Until they see what’s coming over the horizon, moving irrevocably towards them. Their worst mistake. Their darkest fear.And for just one of them, their homecoming.This gripping conceptual horror takes you deep into one of the most macabre and unique imaginations writing in the genre. On family, on children, Lindqvist writes in a way that tears the heart and twists the soul. I Am Behind You turns the world upside down and, disturbing, terrifying and shattering by turns, it will suck you in.