As with the comic book source material, the film features prominent pastiche and crossover themes set in the late 19th century. It features an assortment of fictional literary characters appropriate to the period who act as Victorian era superheroes. It draws on the works of Jules Verne, H. G. Wells, Bram Stoker, Sir Arthur Conan Doyle, H. Rider Haggard, Ian Fleming, Herman Melville, Oscar Wilde, Robert Louis Stevenson, Edgar Allan Poe, Gaston Leroux, and Mark Twain, albeit all adapted for the film.