Thirteen-year-old Gabby Woods is looking forward to another summer vacation at her family's lake house, even though she would rather bury herself in a mystery novel than make new friends. But soon Gabby befriends Paige, a snarky kid from Chicago, and they get caught up in a local mystery: the sudden disappearance of a glamorous couple and the extravagant lake house they left behind. To gather clues about the missing couple, Paige coaxes Gabby into trespassing, even though she knows it's wrong. Yet, each sneaky visit to the abandoned lake house uncovers new mysteries. With suspicions mounting about foul play, Gabby must decide what she's willing to risk to uncover the truth, or if solving this mystery, and keeping her friendship with Paige, are more trouble than they're worth.