Adam (Joseph Gordon-Levitt), a good young man, has a happy life, a smooth job and a harmonious family. Unexpectedly, the back pain that occasionally bothers him is diagnosed as cancer with a 50/50 cure rate. The blow of the disease, the departure of his girlfriend Rachel (Bryce Dallas Howard), and the sadness of his mother make Adam, who was originally confident in facing the disease, gradually feel frustrated and desperate. Only his best friend Kyle (Seth Rogen) has been accompanying him in his unique way. Katherine (Anna Kendrick) is an inexperienced psychologist who is responsible for Adam's emotional counseling. On the surface, she is professional and calm, solving problems for others, but her life and emotions are a mess. Two frustrated people meet in the special environment of disease. From the initial misunderstanding to reconciliation, they gradually feel that perhaps the most important thing in the world is by their side. The film is adapted from the true experience of screenwriter Will Reaser, and the friend who stood behind him and supported him at the time was Seth Rogen, who played Kyle.