Over the summer of 1959, a young girl named Mary Nell becomes obsessed with solving a mystery that occurred in the beachside hotel where she lives with her mother and her 14-year-old brother. Along the way she learns about the ocean, her mother’s history in the hotel, and a few things about love and friendship. After her brother’s girlfriend vanishes under eerily similar circumstances to the old mystery, the original detective reappears, and Nell works to help him solve both mysteries. Originally published in 2019, the author thoroughly revised this work in 2023.