Screenwriters Brian Koppelman and David Levien (Ocean’s Thirteen) recently revealed that they are hard at work on the script for National Treasure 3. The previous two installments of the franchise were written by Cormac and Marianne Wibberly, but the duo decided not to return for a third installment. Producer Jerry Bruckheimer stated last year that National Treasure 3 was in the works but nothing further was heard until now.Director Jon Turteltaub, who helmed the previous two Treasure films, recently signed on to direct the romantic comedy Unreasonable Doubt, but one would assume that he will be behind the camera when National Treasure 3 rolls. In an interview with Done Deal Pro (via Bleeding Cool), Koppelman and Levien also revelaed that they recently completed their adaptation of Levien’s novel City of the Sun which they plan to direct. Hit the jump for more, including a synopsis of the novel.Koppelmana and Levien previously directed 2009’s Solitary Man starring Michael Douglas. City of the Sun is a murder mystery centering on the disappearance of a 12-year-old boy.city-of-the-sun-book-coverHere’s a synopsis of the novel:

Paul and Carol Gabriel are devastated when their 12-year-old son, Jamie, disappears on his paper delivery route one morning. Fourteen months later and with the police no closer to finding Jamie, they hire PI Frank Behr, an imposing ex-cop with a checkered past. Behr soon discovers that Jamie's disappearance was no random grab but part of a larger operation run by Riggi, a real estate tycoon who deals in everything from drugs to stolen children. Reluctantly allowing Paul to accompany him, Behr tracks Riggi's men to Mexico, where he and Paul discover the true extent of Riggi's depravity as they race against the clock to find Jamie. [Amazon].