Two young Englishmen set off on a leisurely sailing holiday in the period before the first World War; however, their lives are threatened after an encounter with a mysterious German yachtsman and his daughter off the North Sea coast of Germany.
Thirteen-year-old Sophie and her cousin Cody record their transatlantic crossing aboard the Wanderer, a forty-five foot sailboat, which, along with uncles and another cousin, is en route to visit their grandfather in England.