They Both Die at the End meets ""You've Reached Sam"" in this heart-stopping speculative young adult novel from New York Times bestselling author Robbie Couch, which explores all the different ways love can endure after tragedy. It's been a year since eighteen-year-old River Lang's best friend died in a car accident. Every day since, he's had to pass by the depressing billboard that appeared as a result: a texting and driving Psa that reduces Dylan to a cautionary tale and River to the best friend of the dead kid at school. Dylan was much more than a statistic, though, and River hates that everyone in town seems to have forgotten. When he's caught improving, a.k.a. vandalizing Dylan's billboard, River is blackmailed into joining the Affinity Trials, a research study observing teens who are ""struggling socially."" But upon arrival, River's social struggles worsen as he's paired with the last person, he wants to spend a week with his ex-best friend and Dylan's former girlfriend, Mavis, who's the only one who knows the truth about the night Dylan died. During the Trials, River befriends a charming quarterback named Nash, and it doesn't take long for romantic feelings to surface. But along with these feelings come bizarre developments within the Trials that make him wonder…