Piper's fall was no accident. Did someone want her dead? It's up to her sister to discover the truth in this shocking new thriller with an unreliable narrator, from the acclaimed author of Little Creeping Things.

Piper Sullivan was in a strange hiking accident last month and has been in a coma ever since. Her older sister, Savannah, can't pretend to be optimistic about it; things look bad. Piper will likely never wake up, and Savannah will never get any answers about what exactly happened.

But then Savannah finds a note in Piper's locker, inviting Piper to a meeting of their school's wilderness club—at the very place and on the very day that she fell. Which means there was a chance that Piper wasn't alone. Someone might've seen something. Worse, someone might've done something. But who would want to hurt the perfect Piper Sullivan and why?

To discover the truth, Savannah joins the club on their weekend-long camping trip on the same mountain where her sister fell. But she better be careful ... everyone in the club is a suspect, and everyone seems to be keeping secrets about that tragic day.

And Savannah? She's been keeping secrets, too.