David and Pennys strange new home is surrounded by forest. Its the childhood home of their mother, whos recently died. But other creatures live here... magical creatures, like tiny, hairy Pog. Hes one of the First Folk, protecting the boundary between the worlds. As the children explore, they discover monsters slipping through from the place Pog calls downways. Meanwhile, David is drawn into the woods by something darker, which insists theres a way he can bring his mother back...