Forty years ago, Sarah Cassidy attended Migawoc Girls' Camp in midcoast Maine where she befriended Myra Huggard, the camp's crotchety neighbor. Today, Migawoc is gone, its land sold off for house lots, but when the elderly couple who ran it invite Sarah to spend the summer in Maine she jumps at the chance to escape her recent divorce and get out on the water in Owl, the camp's old sailboat. Sarah's vacation turns lethal when she discovers that Myra has been murdered, and nearly everyone seems to have a motive. When Sarah and Oliver Wendell, a reclusive boatbuilder who is helping her fix up Owl, start asking the wrong questions, they find themselves being stalked by a killer. To solve the mystery, Sarah must rethink her childhood relationship with Myra, struggling to separate reality from illusion, while also dealing with her troublesome ex-husband and a would-be suitor whose interest may have more to do with murder than romance.