After you vanished / E.A. Neeves.

Neeves, E. A. (Emily Angela), 1987- (author.).

Summary:

"SADIE meets WE WERE LIARS in this heartfelt mystery, in which one girl desperately searches to find out what happened to her missing sister. Teddy's favorite place is Bottomrock Lake, where sunfish swim in their little saucer nests and lilypads edge the shore. She's worked there as a lifeguard every summer, including last year, when her twin sister Izzy waded into the lake for a midnight swim and never came out. Now, Teddy can't stop scripting stories for where she went. Izzy was an accomplished swimmer, so she couldn't possibly have drowned. And if she did somehow drown, where's her body and why is her passport missing? When Toby, the gorgeous jerk who was with Izzy on the night she vanished, comes to Bottomrock to work as a lifeguard alongside Teddy, she can't help but be suspicious. How many of her sister's secrets does he hold? And how can Teddy unearth them-without falling for the boy who watched her sister disappear? Told from Teddy's point of view directly to Izzy, AFTER YOU VANISHED is a mystery that will have readers trying to piece together the secret life of a sister who's gone" -- Publisher's website.