A sinister plot. A hidden city in the sky. A boy with an impossible choice. Twelve year old Toby has little time for friends or football since his mum fell ill. All he wants is to stay at home and keep an eye on her. But mysterious things are happening beyond his garden hedge. Who is the figure at the window behind the barbed wire fence? And why is there a strange woman in his attic with a broken broom and bothersome...