Jack and Annie travel to Vienna, Austria, in 1762 where they meet the young Wolfgang Amadeus Mozart and his sister and help save the budding genius' life.

The lives of the four Weber sisters are changed by the arrival of twenty-one-year-old Wolfgang Mozart, a young man struggling to find his place in the eighteenth-century musical world.

Geronimo travels back in time to help a young Wolfgang Amadeus Mozart, who is the target of the maddest pirate cats' scheme yet. The fiendish felines are in 18th century Italy to steal musical scores by Mozart before he can perform at a historic concert.