The trip to Vienna becomes important when Christopher asks M.T.P.C. to help him look for his diary which he lost on his last trip to the city. They enjoy meeting friends, visiting the opera, the Prater, Schonbrunn, sailing on the Danube and watching how a pastry chef prepares the famous Strudel. The whole time they are looking for the lost diary, even when distracted by Cica losing her keys in the gutter. They also meet with one of the famous Lippizaner horses and visit the studio of a famous weaver and learn the history of kings and queens. The unexpected recovery of the diary makes their stay in Vienna complete.