Hazel Grace Lancaster is 16 and was diagnosed at age thirteen with a terminal form of thyroid cancer that has since spread to her lungs. Hazel can no longer go to school so her parents make her go to a support group in her church everyday.
One day at her support group she meets a cancer survivor named Augustus Waters but does not want to be romantically involed with him to avoid breaking his heart because her life span is limited.
Hazel and Augustus grow closer together through their shared love of the book An Imperial Affliction. The book ends in the middle of a sentence and therefore, doesn't provide a real ending to the book. They decide to write the author but he rufuses to tell them the ending unless they come visit him in person so they plan a trip to Hamsterdam.
Hazel and Augustus are disappointed by Peter Van Houten as they learn he is "pathetic drunk" as quoted in the book. However as result Hazel and Augustus grow closer together and Hazel agrees to have a relationship with Augustus only to learn his cancer is back and is untreatable this time.
As Augustus's health worsens, Hazel and Augustus grow closer and help each other with the physical and emotional pain.
Augustus dies but Hazel is comforted by the eulogy he left behind for her.