Showing Eye of the Storm by Marcia Muller

Appleby Island, once the magnificent home of a tycoon and planter, is a place of history and mystery in the Sacramento delta. Its story includes hints of tragedy, fueling rumors that ghosts still walk its derelict orchards. Now Patsy McCone, her new lover, and a group of investors are turning the old mansion into an elegant bed and breakfast inn. Summoned by her eccentric younger sister, San Francisco's #1 P.I. Sharon McCone arrives in the teeth of a gale, taking a busman's holiday to investigate mysterious acts of vandalism that are running the project to ruin. But when simple sabotage escalates to savage murder, she finds herself trapped on the island with a desperate killer -- and flung into a raging storm of treachery, violence, and sudden death.