Some authors like to include inside jokes, often called Easter Eggs, in their books. Little things that fans might notice but nobody else will pay the slightest attention to. An author's nod to an observant reader. A character from a past book may make a cameo appearance in a new novel, or maybe the same object finds its way into more than one book. Maybe there is a reference to another book or something from the author's life. It's fun to discover an Easter Egg in a book you are reading.

Stephen King is the master of Easter Eggs. He's written 65 novels and over 200 short stories, so he has an abundance of material to drop into books. His books are a regular spider web of towns and characters and scenes that are interconnected in various ways. I found a flow chart online and it looked like the wiring diagram from the Space Shuttle. For example, the characters in "Rose Madder" are reading romance books by Paul Sheldon, a main character in "Misery." One more example is the recurrence of Beverly Marsh and Richie Tozier in both "IT" and "11/22/63." King even refers to Jack Reacher, a Lee Child character in his book "Under the Dome."

King's not the only author that does this. Amor Towles links each of his books to the next through a character. Someone who was merely mentioned in one book becomes a major character in another book. Taylor Jenkins Reid does this too. Mick Riva appears in five of her books, mostly as a minor character. Several of her other characters make appearances in multiple books too. The author of a Star Wars book had some fun with one of the actors in the Star Wars franchise. Han Solo uses the alias, Jenos Idanian, which unscrambles to read Indiana Jones, two roles that Harrison Ford played.

Easter Eggs aren't new. Classic authors created them as well. J.R.R.Tolkien hid messages in the runes decorating the title page of "The Fellowship of The Ring." Margaret Atwood carved a message to her husband into a desk in "The Handmaid's Tale." Lewis Caroll included a poem in "Through the Looking Glass" which if you read the first letter of each line going down, reads "Alice Pleasance Liddle," the name of the girl for whom he created "Alice in Wonderland." In Agatha Christie's "Curtain," the author put a clue in the crossword puzzle one of the characters was working on that pointed to the murderer.

Easter Eggs occur in art, too. If you remember reading Richard Scarry's books, on each page you could find Goldbug doing something interesting.  Comic book artist Todd McFarlane draws hidden spiders on his covers of Spider Man Comics. In Alex Ross's 1996 "Kingdom Come" comic book, behind Superman, you can spot the Village People. Children's author Lemony Snicket's books are full of Easter Eggs, both written and in illustrations. The illustration at the end of each book includes a subtle hint about the next book in the series.

The term Easter Egg started out with computer programmers. Oftentimes they will hide something fun in the code behind programs. Video games often have hidden rooms, or little tricks you can uncover as you play the game. Google (Alphabet) encourages their employees to spend a certain amount of their work time on creative projects, which are sometimes Easter Eggs. For example, open a web browser and pull up the Google search page. Type "play Pac-Man" in the search bar in the middle of the page and you will find yourself reaching for the arrow keys to make sure Pac-Man doesn't get killed by the ghosts.

"Ready Player One" by Ernest Cline hits all the Easter Egg buttons. It's a book about video games and finding Easter Eggs in them. The audiobook is read by actor Wil Wheaton, who is mentioned by name in the book-an Easter Egg.

Easter Eggs are a fun way for authors, artists, and programmers to connect with their audience, and express some playfulness. If you read carefully, you may discover your favorite author uses Easter Eggs too.E