Hazel Lancaster and Augustus Waters meet at a weekly support group meeting for cancer patients, which both are sort of forced to attend. That very same day, their relationship begins with a movie, V for Vandetta, and an exchange of book recommendations. Hazel recommends An Imperial Affliction.
An Imperial Affliction becomes an essential part of their developing relationship. Upon completion, Gus becomes almost as curious as Hazel about how what happens to the characters in the book as the book literally has no ending. So Gus, who is obsessed with living a purposeful life, decides to use his last Wish (via Make a Wish Foundation) to help bring closure for Hazel. Despite several obstacles, both travel to Amsterdam to meet the author of the book himself, Peter Van Houten. Surely, he will know the fate of his characters.