Before the First Curse
At some point in his life, Walt Disney was chosen by Merlin and his apprentice as the Author. Walt served as the Author, recording many fairy tales until his death in December 1966. After Walt's death, the Apprentice hired Isaac Heller as the new Author.
Issac travels the realms of stories and eventually meets Cruella De Vil. Her story is written sometime between meeting Isaac and entering the Land Without Magic. Issac, getting bored with just recording stories, decides to change things. He alters Snow White and Prince Charming's story (He manipulates them into transferring the darkness in their unborn daughter into Maleficent's baby). Because of his actions, the Apprentice imprisons Issac in the book, in an illustration of a locked door.
During the First Curse
When the Dark Curse is cast, the book, along with most of the Enchanted Forest is sent to the Land Without Magic, coming into Snow White's possession. She gifts the book to one of her student, Henry Mills, to cheer him up. After reading some of the book, Henry becomes convinced that most of the town is under a curse, and that they are all fairy tale characters who were trapped in this land by the Evil Queen (also known as Regina Mills, his adoptive mother). Henry manages to track down his birth mother (Snow White and Prince Charming's child), purposely leaving the book in her car after she returns him to Storybrooke.
Henry rips the last few pages out of the book (the one's that show Emma's birth), so that Regina cannot see them.
Pinocchio, under the alias of August Booth, eventually arrives in town and adds his story to the book as well.
After accidentally being poisoned by one of Regina's apple turnovers, Henry is rushed to the hospital. There Emma discovers the book in his bag, and remembers her parents placing her in the magical wardrobe before the Dark Curse came.
After the First Curse
When the town residents discover that crossing the town border would result in memory loss, Charming searches for a way to bring Emma and Snow back after they were pulled into a portal of a magic hat owned by Jefferson. After Henry looks through the book and realizes Jefferson is the Mad Hatter, he sets out with Charming to find Mr. Gold, so that Gold can help them find Jefferson to reactivate the hat.
After August is given a second chance at life by turning back into Pinocchio, his father Marco keeps some of his old belongings in their workshop, which included the page with the illustration of the locked door that Isaac was trapped inside of.
After the Second Curse
When Emma unknowingly brings Robin Hood's wife Marian back with her from the Enchanted Forest, Robin chooses to stay with his wife and ends his relationship with Regina. Angry and frustrated she summons Sidney, expressing her desire to find the Author so that she can make him write a happy ending for her, with Robin.
Henry joins her search for the Author after she asks him about the author's identity. Believing that Gold knows something about the Author, Henry takes up an apprenticeship in his shop to search for answers.Regina tries to prove to Robin Hood that they cannot be together by showing him the storybook, and the ending to his story. Robin then researches the book at the library where he discovers a new page showing him and Regina together, giving both of them a new hope.
Sneaking around the Sorcerer's mansion, Henry comes across a hidden library filled with empty storybooks, and later brings Emma and Regina to the site. Regina believes the Sorcerer to also be the Author, and with the help of Belle, and advice she got from an "Oxford Professor" she talked to online (who was really Mr Gold), frees the nuns who were trapped in the Sorcerer's hat. Regina then shows one of the empty storybooks to Mother Superior, who states that the Sorcerer and the Author are not the same person, and that only the Author can help them. After being asked by Emma why the Author disappeared, Mother Superior says she does not know, but believes there are clues in the storybook to explain it.Later, Regina discovers some of the pages in Pinocchio's story look different from the others. Suspecting that Pinocchio knows something about the Author, she goes to question him. However Pinocchio remembers nothing. An angry Regina vents her frustrations on the boy. She later apologizes to Marco about her treatment of Pinocchio, and Marco gives her Pinocchio's old bag from when he was still August. After dumping out the contents, Henry discovers the page with the illustration of the door with a sticky note attached referencing the Author. After Pinocchio is restored to his former self, he reveals to Regina, Emma and Henry that the author is trapped inside the door on the page.
Later Emma and Regina are trying to decide how to proceed after finding out the truth behind the drawing of the door. Using her magic, Emma creates a fake copy of the page she hopes they can give to Gold and his allies (Maleficent, Ursula and Cruella) to deceive them. However, Regina takes a photo of the page and keeps both copies of the page safe within the storybook.
After hiding out in the Sorcerer's mansion from Maleficent's sleeping spell, Henry waits for Snow and Charming to meet up wit him. While waiting he sees a light coming out of the keyhole of the door illustration. the light leads him to a drawer where he finds a key. Regina (who has been pretending to befriend the villains to find out what they are after) bursts in with Maleficent and Cruella. Regina gives Henry a look, and he realizes she wants the fake page. He gives her the fake one and the three depart. Soon, Snow and Charming show up, and after Henry tells them about the key, they ask Henry to hand both the key and the illustration over to them. Confused he hands over both and leaves, carrying the storybook with him.
After the villains interrogate Pinocchio (who is now transformed back to August), he reveals to Emma the history of the author, and she unlocks the drawing, freeing Isaac from the page. Snow And Charming realize he was the peddler that led them to the apprentice in the Enchanted Forest, and he runs away. Emma chases after him, but he disappears.
After the Third Curse
After Henry learns that the Author's quill was sent to the Underworld after he broke it, he searches for it, as he is tired of sitting on the sidelines doing nothing while his family continue to save Storybrooke. He finds it in the Sorcerer's mansion, after Liam Jones finds the Underworld copy of the storybook.
This version of the storybook appears to have several stories about the souls trapped in the Underworld. Its last story was also about the leader of the Underworld, Hades, before it was ripped out by Liam. Other stories that are seen are Cruella's request to have Henry help her find the quill, and the mutiny aboard Captain Silver's ship, led by Liam.
During Zelena and Belle's arrival in the Underworld, Henry manages to write a few new stories for the Underworld edition of the book, particularly one about Snow and Charming's attempts to contact their son, Neal, back in Storybrooke.
When a portal to Storybrooke opens, Henry begins to write down everyone's unfinished business so they are able to move on from the Underworld, before being trapped by Cruella and the Blind Witch in the Underworld library.
When Hades escapes the Underworld, Killian Jones tries to find a way to defeat him. Knowing that his weakness is most likely in the book, Hook searches for the pages that his brother ripped out. He goes to ask Cruella where the book is and discovers that she disposed of it in the River of Lost Souls. Accompanied by King Arthur, Killian journeys to the River to retrieve the book.
When Henry sets out to destroy magic once and for all, he travels to New York City on a mission, accompanied by Violet. He discovers that his father had come close to destroying magic before his death, but was unsuccessful. While Henry and Violet search the New York Public Library for answers, they discover a second volume of the storybook that contains several new stories including, among others: The Strange Case of Dr. Jekyll & Mr. Hyde, Gulliver's Travels, Twenty-Thousand Leagues Under the Sea, Paul Bunyan, and The Three Musketeers. 
- The Author is not allowed to write their own happy ending in the book or they will be fired.
- It is unknown which stories Walt wrote, and which ones Issac wrote.
- The show implies that Issac wrote Cruella's story and thus the story of 101 Dalmatians.
- This is interesting, since the film version of the story was made and released during Walt's life (in 1961), before Isaac would even be able to discover the existence of Cruella, meaning that Walt should have written her story and not Isaac..
- The show implies that Issac wrote Cruella's story and thus the story of 101 Dalmatians.
- Henry is the only known Author to possess the storybook before getting the position.
- There may possibly be other Once Upon a Time Storybooks in existence, as Henry states that Dr. Frankenstein does not appear in the book, despite appearing in Storybrooke as part of the curse, and the existence of the blank books in the Sorcerer's mansion.
- Due to the existence of Dr. Frankenstein in Storybrooke, it is very likely that Mary Shelley was also a previous Author that was chosen by Merlin and the Apprentice, and subsequently replaced after her death in 1851.
- Based upon the characters seen on the show, other possible previous Authors can include: The Brothers Grimm, Charles Perrault, Hans Christian Andersen, L. Frank Baum, William Shakespeare, and Robert Louis Stevenson.
- A second volume of the storybook was revealed to exist in the Season 5 finale. It is quite possible that Dr. Frankenstein's story appears in that edition.
- It is implied that characters who appear in the book were the ones who were taken to the Land Without Magic during the Dark Curse.
- It is unknown if the story of 101 Dalmatians exists in Henry's book, or in another. Since Pongo came to Storybrooke with the curse, the story had to have existed in one of the storybooks.
- Cruella most likely would have come through with the Dark Curse along with Pongo (and would have subsequently lost her memories) if she had not already entered the Land Without Magic prior to the curse being cast.
- It is unclear why some characters from fairly tales in the book were affected by the curse, whereas others from the same fairy tale stayed in the Enchanted Forest. An example of this is The Little Mermaid. Prince Eric was taken by the curse, and lived in Storybrooke while Ariel was still in the Enchanted Forest. Ursula had come through prior to the curse along side Cruella.
- It is currently unknown who made the book. It is unknown if it was made by Merlin, the apprentice, or one of the various Authors throughout history.
- The Underworld version of the book appears to be a separate copy from the one Henry owns. As it records the stories of those in the Underworld, all of the characters original stories most likely appear in another storybook, and are continued in the Underworld version when they arrive.
- Hades seems to be the only person whose story originally appears in the Underworld version
- It is currently unknown who wrote the Underworld storybook. It could be a previous, dead Author, or someone else entirely.