Complex sentence: The organization appears in the novel "The Saint and the Fiction Makers", written by Fleming Lee and credited to Leslie Charteris, who served an in an editorial capacity and who created the title character of Simon Templar, alias "The Saint".
Split into simpler sentences: The organization appears in the novel "The Saint and the Fiction Makers", written by Fleming Lee. It is credited to Leslie Charteris, who served an in an editorial capacity and who created the title character of Simon Templar, alias "The Saint".