The Last Guest House: Some Secrets the Tide Keeps. The Last Guest House Trilogy, #1

Some secrets the tide keeps. Some it gives back. When Mara Vale inherits a weathered guest house on a private New England island, she plans to reopen it, stabilize it, and leave. She is a former crime reporter - disgraced, careful now, done with other people's disasters. The Last Guest House is a business problem, not a calling. Then a guest is found dead in the tide room below the inn, and Mara discovers she is already inside someone else's story.
The island belongs to the Harrow family. It has always belonged to the Harrow family. Old money, old silence, old names on old records - and every guest who arrived that weekend had a reason to lie about why they came. The polished travel writer who knew too much about the house's history. The family heir with the going coat and the practiced charm. The matriarch who arrived by private water taxi and expected every room to adjust to her.
The soft-spoken administrator who remembered exact times and managed inconvenient realities. One of them killed Evelyn Wren. And Evelyn Wren, Mara is beginning to understand, was not simply a journalist covering a reopening. She was the latest in a chain of people who had come to Harrow Isle looking for the same buried thing - and finding it too completely. The murder is the surface. Beneath it: a woman erased from the island's records sixty years ago.
A property document with a missing page. A name altered in a chapel registry. And a guest house that Mara's late aunt did not leave her out of sentiment - but because this building, and the tide room beneath it, and the stone archive below that, hold the evidence of a fraud that changed who owns this island and who was allowed to exist on it. The Last Guest is the first book in The Last Guest House Trilogy - a series of atmospheric island murder mysteries in which every season brings a new death, and the buried truth gets harder to bury.
Fair-play clues. Multiple suspects. One satisfying reveal - and questions that run deeper than the murder. For readers of Ruth Ware, Lucy Foley, and Agatha Christie.