The heavy cream envelope arrived on Tuesday morning, delivered by hand when I wasn’t expecting anything at all. My name was printed elegantly on the front in silver ink: Mrs. Abigail Thorne. Inside was thick parchment paper embossed with a crest—a castle tower pierced by a crescent moon—and an invitation to Castle Montclair for a “Wellness Week of Earthly Delights.” A single line below the formal wording caught my breath:...