The Map and the Stone — Sarah Barnard

Rhys is ten years old and he lives, with his Mum, in a tiny house on a council estate. Rhys is called a daydreamer by his teacher ay school, and he's always staying behind to finish his work. But, out of the corner of his eye, Rhys sees thing moving, in the hedges, in the trees, and then... There's a Darkling on his bed, and it needs his help. Haunted by the dying Darkling, Rhys must find the magical Nexus to find a way home for the last living Darklings.