Ajvide Lindqvist, John: Let the Right One in

Oskar and Eli. In very different ways, they were both victims. Which is why, against the odds, they became friends. Oskar is a 12 year old boy living with his mother on a dreary housing estate at the city's edge. He dreams about his absentee father, gets bullied at school, and wets himself when he's frightened. Eli is the young girl who moves in next door. She doesn't go to school and never leaves the flat by day. She is a 200 year old vampire, forever frozen in childhood, and condemned to live on a diet of fresh blood.