"They Both Die at the End" is a young adult novel by Adam Silvera that explores themes of mortality and friendship. The story follows two teenage boys, Mateo Torrez and Rufus Emeterio, who receive a call from Death-Cast, a service that informs people when they are going to die within the next 24 hours. As they navigate their final day, Mateo and Rufus meet through an app called Last Friend and decide to spend their last hours together. Their journey highlights the importance of living life to the fullest and forming meaningful connections, even in the face of inevitable loss.