Peter Jackson is secretly working to adapt the “Mortal Engines” fantasy novels for the screen, reports the Dominion Post. The hush-hush project is understood to be in early development, with work on the first of the four books under way, they add. Weta Workshops is also believed to be working on designs for the science fiction series, which features giant mobile cities. The books, by Philip Reeve, are set in a post-apocalyptic world where cities have become giant vehicles and must consume each other to survive. “Mortal Engines” is the first book in the series, and has won a Nestle Smarties Book Prize and was shortlisted for the 2002 Whitbread Award.