Warner Bros. has acquired the upcoming Philip Reeve penned children's book Railhead, with Doug Liman in negotiations to direct.The novel, which is aimed at readers between 10 and 11 years old, is set in a futuristic world where trains travel through outer space by a series of portals. The story centers on a young thief who is hired to steal an object that is much more important than he is lead to believe, which starts him on an adventure that could alter the course of the universe.Denise Di Novi and Alison Greenspan are producing the adaptation through their Di Noi Pictures company.