Maisie is a 16-year-old girl who loves running, her friends, school, and her boyfriend. Her life seems average, despite the constant fights her parents have, until one day, fate changes everything. One early morning, Maisie wakes up at dawn to go for a quick run before school, and ignoring the heavy fog and weather warnings, she sets out to the field by her house. After around 30 minutes, the clouds start to get heavy, and Maisie turns around. Suddenly, Maisie is caught in a harsh storm. As the rain poured down, an electrical fire struck up, capturing her in its walls of fire. A month later, Maisie wakes up from a coma in a hospital. Unaware of what happened and confused by her surroundings, Maisie quickly tries to ask but is shut down by her hoarse voice and instead is brought water. Eventually, the series of terrible events is explained to her. Maisie is given a day or two to recover, and then she is asked to make one of the biggest decisions of her life. Maisie is asked to choose whether or not she wanted to get a face transplant. Given a short period of time to think, Maisie goes through the pros and the cons, carefully deciding which has more value, and she decides to go through with the transplant. The surgery is long, dangerous, and terrifying. When Maisie wakes up, she is scared, scared of the bandages over her eyes, scared of the possibilities of what could have gone wrong, scared of how she looks. The whole left side of her body is tight, making it nearly impossible for her to sit up. After Maisie recovers enough, it is time for her to begin physical therapy, or PT, with Marnie. Marnie is cheery, beautiful, bright, and everything Maisie hates. After a few weeks, nearing the end of the summer, Maisie is finally released from the hospital.
After being released, Maisie has to go back to school during the new school year. Uninformed until that morning, Maisie's boyfriend, Chirag, takes her. School is hard for Maisie. She isn't able to join in on the senior tradition, sitting on the bleachers, because of the bright sun on her sensitive skin. Seeing the pity and fear in people's faces that knew her before makes her shy. Her medicine keeps her exhausted, and the nightmares she is having only makes it worse. To add on to her problems, she always has to visit the nurse and sometimes misses out on lessons. Maisie starts to realize that she isn't the same old Maisie she had expected would return. She can't run, her grades have dropped, and her relationship is starting to fail. Before Maisie knows it, it's time for the Halloween dance. At the dance, Maisie gets separated from her best friend, Serena, and Chirag. Searching for either of the two, Maisie comes across where all the seniors are hanging out this year, only she wasn't told about it. She overhears Chirag and a few of his friends talking about Maisie and Chirag's relationship. Chirag describes his position as a nurse for Maisie. His friend suggests that Chirag move on and dates another girl, who's a year younger. Upon hearing this, Maisie's heart is broken. She wants to be the old Maisie again, the one Chirag can love. So she comes up with a plan.
Maisie, without any research or preparation, decides to go off her medicine. She thought that this would make her less tired so she can get better grades, run, and spend real time connecting with Chirag. She is happier, more active, and much less tired. All is going well until her mother finds an excess amount of pills left in her bottles. Maisie and her mom have a huge fight, ending with her mother giving her some pictures and telling her, "It's your choice. Life. Or death." Although Maisie thought that she had had an amazing idea, she decides that she wants to live. She wants to continue, even though there would be terrible struggles. As Maisie transitions back onto her meds, she starts to become depressed. She stays inside more, especially since it is December now, and she doesn't talk to Chirag that often anymore. Noticing this, her parents talk to her doctors and decide to search for a group for trauma recoverers. They eventually find a group and take Maisie. At the group, Maisie meets Adam, a trauma victim from war. Adam and Maisie talk a lot, and soon Adam asks her to go out for food with him sometime. After a few more visits to group, Maisie considers how her relationship with Chirag is going. One night, when Chirag picks her up, she just lets go. She tells him that she heard what he said and how she feels. She breaks up with him and doesn't talk to him the rest of the car ride. The next group, she decidsd to say yes to Adam's invitation. That night, she asks Adam to senior prom but runs out embarrassed before he can answer. Later that week, Adam comes over and explains to Maisie that he is dating Marnie, but they could still go as friends.
Through group, Maisie adjusts to her new life--not fully, but she has learned to accept it. She has even jogged with Adam. Now, with prom coming up, Maisie has a plan to deal with her breakup with Chirag. She wants to apologize and just tell him that she is sorry for never telling him, "I love you, too." With the prom approaching, Maisie decides to go just with Serena. While preparing for prom, Serena tells Maisie something extremely important. She explains that when Maisie was hospitalized, Chirag took the tree that caught fire and brought it up a tall hill and created a fire. That night, Chirag was almost arrested. At prom, Maisie and Serena hang out for a little bit but eventually split off. Maisie finds Chirag, who leaves his date to talk to Maisie. Maisie tells Chirag everything she wanted to say. She exchanges the words "I love you, too," at last.
Maisie learns to love the new her. She realizes that she'll never be the same. However, she also realizes that not everything is going to change and not everything needs to change. She still has the same friends and family, and those people will always support her. She can live like this, and she realizes that she is lucky.