Sometimes when a book is being adapted for film, aspects of the source material must be expanded for the screen. That is the case for An Imperial Affliction in The Fault in Our Stars.

In a Tumblr post Friday morning, The Fault in Our Stars author John Green confirmed that he wrote four pages of the faux book An Imperial Affliction by Peter van Houten after a request from executive producer Isaac Klausner. Filmmakers needed some of the book for the film when they show Hazel reviewing the story and the all-important line, “Pain demands to be felt.”

Green wrote on Tumblr, “Klausner asked me to write four pages (the two you see here and the final two pages of the book) for the movie edition of An Imperial Affliction, so I did. In this passage, Anna is recalling intense pain breaking through her high doses of narcotic pain medication.

“The book that Hazel reads in the movie is just the four pages I wrote printed over and over again hundreds of times. I have a copy of it in my house; it’s my only souvenir from the movie set.”

Check out one passage from the film below:

An Imperial Affliction is Hazel Grace’s favorite book because of the parallels she draws between its lead character and herself. She and Gus travel to Amsterdam to meet the author, who surprises them with his unkind attitude.

Green shared the tidbit after he received questions from those who are watching The Fault in Our Stars at home thanks to this week’s release on Digital HD.

While you can download the film now, Fault won’t hit DVD and Blu-ray until September 16.

Both the Digital HD and physical copies include an extended version of the film with several deleted scenes. Watch one of them here!