Two teenagers, Mateo and Rufus, receive the Death-Cast call, telling them that they will die within the next 24h. One is a lonely guy whose father is in a coma. The other just made a mistake by beating his ex-girlfriend new boyfriend and the police interrupts his goodbye funeral. The two teenagers use the Last-Friend app to not finish the day alone end up meeting each other. Mateo being easily scared learns how to live from Rufus. Rufus learns how to settle in his life with Mateo. Eventually a love attraction rises between them. It will last only a few hours before Mateo dies from a stove explosion and Rufus from a car hit.
This book was easy to read even though there are some lengths that I skimmed quickly. The story is interesting to showcase the difference between being and living. I don't think it goes very far beyond that.