Simon's Dream: The Fog Mound Series #3 by Susan Schade, Jon Buller (Illustrator)
Thelonious Chipmunk and his friends face a whole new series of adventures after they reach the mysterious Mattakeunk Institute and discover...a time machine! Will the time machine lead them to the answers they seek? Perhaps some of the answers will come when the animals' traveling companion, Bill the Human, regains his ability to speak. However, there is one pressing need above all others -- the need to save their beloved Fog Mound from the Dragon Lady herself, and her evil ratmink assistants. Find out more about the author and illustrator here.