Best friends, Cynthia and Gus as she prefers to be called, are as "different as bubble gum and broccoli." They are, however, equal in their ability to get into trouble without much effort. In trying to escape the "boring summer" of 1964, the adventurous twelve-year-old girls stumble upon a trunk in Cynthia's attic that has been in her family for three generations. They discover its mystical qualities when they are swept into the trunk and whisked back to 1914, literally into the lives of their twelve-year-old grandmothers, Clara and Bess. The mystery of a missing family locket is revealed. Their quest takes numerous twists and turns, including a life-and-death struggle on a large steamship traveling from England to America. Along with perilous escapades, they make important, sometimes humorous discoveries about their ancestors, and even manage to change history?for the better?along the way.