Shortly after the previous Author passed away, Isaac was given the position of being The Author, whose job it was to document the events of the Enchanted Forest. However, Isaac abused his power and began manipulating events in order to write better stories. This prompted the Sorcerer's Apprentice, whose master gave Isaac the title and power, to trap Isaac inside his own storybook, as he is unworthy to be the Author.
Emma Swan, Snow White, David Nolan, Regina Mills, Henry Mills, Rumplestiltskin, Maleficent and Cruella De Vil all search for the Author relentlessly, with the heroes' goal to give Regina a happy ending, while the villains desire to get their own happy endings by destroying the heroes' happy endings. When Pinocchio reveals that the Author is trapped in the storybook, Henry finds the key at the Sorcerer's mansion and frees Isaac from the storybook. Snow and David recognize him as a peddler they once met, and Isaac runs away, escaping. Isaac runs into Rumplestiltskin, and goes with him, where it is revealed that Cruella and Isaac met in 1920's England, which ended in Cruella murdering her mother. This prompted Isaac to take away her ability to kill others, which he reveals to Snow and David when Cruella holds Henry hostage. However, Emma doesn't know this and ends up killing Cruella. Regina obtains suitable ink with a sample of Lily's blood, which is tainted with Emma's darkness. However, when Regina decides that she doesn't want Isaac to write Zelena Mills out of existence, Isaac becomes irritated and leaves with the magic ink to Rumplestiltskin, and writes another story where the villains get their happy endings. However, the story is reversed, with Isaac's work undone. Isaac attempts to flee, but is caught by Snow and David and taken into custody. Isaac is imprisoned in the asylum beneath the hospital.
When Henry starts being controlled by his Author powers, Regina confronts Isaac in his cell, demanding answers. Isaac, however, has demands of his own - such as freedom to leave Storybrooke for New York.
He tells Henry and Regina that Henry is coming up to the final chapter, the final battle, and leaves Storybrooke.
- None known (family)
- The former Author was Walt Disney, who died in December 1966.
- Isaac mentions having a bar mitzvah, which implies that he is Jewish.
- S4, E16: "Best Laid Plans"
- S4, E17: "Heart Of Gold"
- S4, E18: "Sympathy For The De Vil"
- S4, E19: "Lily"
- S4, E20: "Mother"
- S4, E21: "Operation Mongoose, Part One"
- S4, E22: "Operation Mongoose, Part Two"
- S6, E16: "Mother's Little Helper"