Things never seem to go as easily for thirteen-year-old Frankie as they do for her twin sister, Tess. Unlike Tess, Frankie is neurodiverse. In her case, that means she can’t stand to be touched, loud noises bother her, she’s easily distracted, she hates changes in her routine, and she has to go see a therapist while other kids get to hang out at the beach. It also means Frankie has trouble making friends. She did have one–Colette–but they’re not friends anymore. It’s complicated.

Then, just weeks before the end of seventh grade, Colette unexpectedly shows up at Frankie’s door. The next morning, Colette vanishes. Now, after losing Colette yet again, Frankie’s convinced that her former best friend left clues behind that only she can decipher, so she persuades her reluctant sister to help her unravel the mystery of Colette’s disappearance before it’s too late.