"Twins Ethan and Ella are about to go on the trip of a lifetime: a journey around the world! As their adventures begin, however, mysterious things start to happen. Before the twins even leave, Ethan's special gold coin goes missing. On their first stop, in Venice, Italy, the twins meet a man whose boat has been taken! It's up to Ethan and Ella to find it. And in Paris, France, a precious painting is stolen from a museum, and the twins follow clues to catch the thief. Join Ethan and Ella on their adventures as they solve one mystery after another!"--page 4 of cover