The Many Half-Lived Lives of Sam Sylvester

Sam Sylvester has long collected stories of half-lived lives--of kids who died before they turned nineteen. Sam was almost one of those kids. Now, as Sam's own nineteenth birthday approaches, their recent near-death experience haunts them. They're certain they don't have much time left. . . .
But Sam's life seems to be on the upswing after meeting several new friends and a potential love interest in Shep, their next-door neighbor. Yet the past keeps roaring back--in Sam's memories and in the form of a thirty-year-old suspicious death that took place in Sam's new home. Sam can't resist trying to find out more about the kid who died and who now seems to guide their investigation. When Sam starts receiving threatening notes, they know they're on the path to uncovering a murderer. But are they digging through the past or digging their own future grave?