This is a perfect book for summer. The book opens in the small-town of Littleport, Maine, a vacation spot and harbor town. Avery and her best friend, Sadie, attend the annual “Plus One” end-of-season party, as they do every year. However this year, Sadie turns up dead and the police rule it a suicide. But Avery doesn’t believe her best friend would do that and begins to investigate on her own. But the more Avery digs, the more suspicious she looks to the local police, and this is a fun twisty who-done-it thriller. The book bounces back and forth between the summer Sadie died and the next summer, when Avery uncovers new clues. It’s a fast-moving story where no one is telling the whole truth and you don’t know who to trust.