Wren and Lewis are a couple characterized by their differences. Wren is an obsessively organized financial worker, and Lewis is an impractical and artistic theater teacher. They meet at a Dallas cafe in 2012 when Lewis is on a first date with another woman, both of them having moved back home to the Great Plains after pursuing careers in other parts of the country. Early in their relationship, Lewis struggles with Wren’s aversion to emotional vulnerability. He finds that he enjoys how her practicality enables his artistic pursuits, however, and they eventually decide to get married.

Shortly after the wedding, he begins to notice strange changes happening to his body. Most notably, his skin has become sandpapery and his nose has become entirely cartilaginous. He goes to the doctor, who diagnoses him with an irreversible Carcharodon carcharias mutation: Within a year, Lewis will turn into a great white shark. At first, Lewis hides the news from Wren, wanting to process the existence of the illness for himself. Unbeknownst to him, Wren is hoping that they might begin trying to have a baby. Lewis breaks the news to her the same night that she plans to ask him how he would feel about having children.