Aria, the world traveler, gets invited to a singing competition in Italy. The winning choir will sing for the Pope. Aria, Daisy, and choir members enjoy visiting the Sistine Chapel. After their tour guide tells them a mystery connected to the Sistine Chapel, three choir boys disappear one by one. As Aria and Daisy go on a mission to find the missing boys, they find an unexpected ancient treasure that will help them win the competition. This book series...