Now that the twins have begun to settle into their new lives at Elm Medona, they delve deeper into The Treasure Chest and uncover more about the Pickworth family, including the disappearance of their great-uncle Thorne and the theft of priceless family artifacts. In this adventure, The Treasure Chest transports Felix and Maisie to tropical St. Croix in 1772. There they meet a young man named Alexander Hamilton who is about to embark on a journey to New York. Felix and Maisie aren't sure why The Treasure Chest has brought them to meet Alexander, but they are determined to not let him out of their sights . . .even if that means stowing away on the very ship he is sailing off on!