Jack and Annie travel 500 years back in time to Florence, Italy, and spend a day helping Leonardo da Vinci in the hope of learning another secret of happiness. Includes temporary tattoos.
Jack and Annie continue to try helping Merlin the magician by searching for the secrets of happiness, and their magic tree house takes them to Antarctica, a wasteland where the penguins may know what to do.
The Magic tree hous takes Jack and Annie to San Francisco in 1906, in time for then to experience the biggest earthquakes the United States had ever known.