Weeks later, Augustus tells Hazel that he has traced Van Houten's assistant, Lidewij (Lotte Verbeek), and has corresponded with Van Houten by email. Hazel then writes to him to find out more about the novel's ambiguous ending and Van Houten replies that he is only willing to answer her questions in person. Overwhelmed and excited, Hazel asks her mother if she can travel to Amsterdam to visit him, but Frannie rejects it because of financial and medical constraints. Augustus suggests that she use her "cancer wish" since children and young adults with life-threatening illnesses receive one arranged experience of their choice, but Hazel explains that she already used hers to visit Disney World when she was younger. Augustus and Hazel go on a picnic date and soon begin to fall in love. Augustus also surprises Hazel with tickets to Amsterdam after using his wish on her. However, days before the trip, Hazel suffers from pleural effusion and is sent to an intensive care unit (ICU). Although