•All with their original illustrations by Edward Gorey, Mercer Mayer, and Richard Egielski, respectively.
•Each chapter head of 'The House with a Clock in Its Walls' has its own individual spot illustration by Edward Gorey along with eleven full page illustrations.
•'The Figure in the Shadows' has fourteen full-page illustrations by Mercer Mayer.
•'The Letter, the Witch, and the Ring has thirteen full-page illustrations by Richard Egielski, who also creates individual mini-illustrations for the chapter heads of all thirteen chapters.
•Each novel's pages are individually numbered.
