 He also began a 13-book series of young-adult novels about a series of adventurous teenagers, who are destined to save the world from an evil being, Solaris.He claims the latter is a mix of "The Famous Five" and "Indiana Jones", titled "The Last Thirteen" and they are under contract with Scholastic Publishers for publication monthly from December 2013 through to December 2014.Scholastic renewed the series, the first book titled "X", for publication in 2017.