"The prequel to They Both Die at the End"--Dust jacket.

Series title from Goodreads.com.

"In this prequel to #1 New York Times bestselling phenomenon They Both Die at the End, two new strangers spend a life-changing day together after Death-Cast first makes their fateful calls. It's the night before Death-Cast goes live, and there's one question on everyone's mind: Can Death-Cast actually predict when someone will die, or is it just an elaborate hoax? Orion Pagan has waited years for someone to tell him that he's going to die. He has a serious heart condition, and he signed up for Death-Cast so he could know what's coming. Valentino Prince is restarting his life in New York. He has a long and promising future ahead and he only registered for Death-Cast after his twin sister nearly died in a car accident. Orion and Valentino cross paths in Times Square and immediately feel a deep connection. But when the first round of End Day calls goes out, their lives are changed forever--one of them receives a call, and the other doesn't. Though neither boy is certain how the day will end, they know they want to spend it together... even if that means their goodbye will be heartbreaking. Told with acclaimed author Adam Silvera's signature bittersweet touch, this story celebrates the lasting impact that people have on each other and proves that life is always worth living to the fullest"--