One of Us Is Back (ONE OF US IS LYING) by Karen M. McManus

The global phenomenon returns with the third book in the One of Us Is Lying series, from #1 New York Times bestselling author Karen M. McManus. When someone from the Bayview Four’s past resurfaces, history begins to repeat itself—and the consequences are deadly.

The third time’s a charm.

It’s been almost two years since Simon died in detention, and the aftermath has been hard to shake. First the Bayview Four had to prove they weren’t killers. Then a new generation outwitted a vengeful copycat. Now the entire Bayview Crew is back home for the summer, and everyone is trying to move on.
 
Only, this is Bayview, and life is never that simple.
 
At first the mysterious billboard seems like a bad joke: Time for a new game, Bayview. But when a member of the Bayview Crew disappears, it’s clear this “game” is serious—and whoever’s in charge isn’t sharing the rules. Or maybe there aren’t any.
 
Bronwyn. Cooper. Addy. Nate. Maeve. Phoebe. Knox. Luis. Kris. Everyone’s a target. And now that someone unexpected has returned to Bayview, things could start getting deadly.
 
The thing is, Simon was right about secrets—they all come out eventually. And Bayview has a lot it’s still hiding.