They Both Die at the End

They Both Die at the End is a young adult novel by Adam Silvera, published on 5 September 2017 by HarperTeen. It is his third novel and follows two teenage boys, Mateo and Rufus, who learn that they have one day left to live.

The device that starts the plot is a company. Death-Cast can predict individual deaths, and it calls Mateo shortly after midnight on 5 September to tell him that he is a Decker, a person with twenty-four hours or less remaining. Both he and Rufus are looking for company on their final day, and the app Last Friend is designed to connect lonely Deckers with someone to spend it with. Mateo is introverted by temperament and decides that the day has to be spent living properly, while Rufus takes his call in the middle of a fight and then has to leave the household that took him in.

The novel's structure means the title is a promise rather than a threat, so the reading experience is about how the day is spent rather than whether it ends. In April 2020 the book's sales revived through BookTok, the reading community on TikTok, and it returned to the New York Times Best Seller list more than two years after publication.