Martha's Vineyard has always been known as a charming seaside destination. But on this island, a cautious tour reveals darker tales that lie beneath its familiar exterior. Walk by the House of Correction, where Old Joe patrols the cells in the afterlife. Savor spirits at the Kelley House, where the ghost of the widow of a whaleman rolls Christmas ornaments across the floor and appears by the fireplace. Meander into the Victorian Inn, now The Christopher,...