Eleven-year-old twins, Josh and Lizzie Parker, and their travel-blogging parents are off on a new adventure, this time to Nantucket Island off the coast of Cape Cod, Massachusetts. Aboard a ferry to the island, the twins meet Sara Coleman Clarke, or Grams, as her friends call her. Grams is desperate to boost her struggling family museum and has organized a Spyglass Spectacle gala to raise money for exciting improvements. Baxter Benedict, a long-time...