Sammy and the Sobiechs learn that Zach might not make it to prom.
Zach speaks privately to his mother about how to handle his remains and his funeral, suggesting bagpipes be played. Zach finally makes the time to apologize to Amy about his behavior and the two of them get back together. On the flight back home, Zach suddenly has a moment of creative energy and writes the song " Clouds" and records it shortly afterwards, becoming a colossal hit. They head to New York City to sign their contracts, calling their band A Firm Handshake ("Ames"). In the spring of 2013, Weaver reveals to Zach and Sammy that he showed their video to BMI and that they want to sign them. Laura confronts Rob over the decision to get a car for Zach and he breaks down admitting that he did it to make his son happy as he is unable to do anything about his eventual death. While at her house, the two proceed to make out ("My Little Dancer"), but when Amy comments on his scars, Zach becomes despondent and tells her that he will never offer the things she wants from him and breaks up with her while leaving in a huff. Zach's father, Rob, borrows a Nissan GT-R for him to drive and impress Amy with. Despite this, Zach is certain that he will fail to achieve anything beyond the video. They continue to bond over songwriting ("Fix Me Up") and Sammy posts their music on YouTube which earns them some fame.
Both realize that they have romantic feelings for each other, but that they are incapable of having a full relationship. After having convulsions, Zach goes to Sammy's house in the middle of the night demanding that they form a band. Zach decides to use the opportunity to ask Amy out to prom and she accepts (" I'm Yours"). Zach returns home to hang out with Sammy ("Coffee Cup") and learns that she has bought tickets to a Jason Mraz concert. In the winter of 2012, Zach and his family go to Lourdes, France, in Laura's desperate attempt at Zach having some sort of miracle. Zach tells Sammy and Amy about his diagnosis while he is inspired by his teacher, Milton Weaver, about what he is to do with the rest of his life. While they fix his lung, they learn that the treatments are no longer effective and his cancer is now terminal, giving him six to ten months to live. He has a collapsed lung and emergency surgery is performed on him. Zach manages to ask out fellow student Amy Adamle for a picnic, but before he is able to do so, he begins to have a coughing fit that concerns his mother, Laura, who rushes him to the hospital. His best friend, Sammy Brown, conspires with him by helping him to write music ("Blueberries"). Zach has been struggling with osteosarcoma and has been receiving regular treatments for it. In the fall of 2012, Zach Sobiech performs an acoustic rendition of " Sexy and I Know It" to an amused crowd at his school's talent show.