In the wake of Mr. Tyco Bass's disappearance, his cousin Theo arrives at Thallo Street and proposes a return trip to Basidium. Then ambitious astronomer's assistant Horatio Q. Peabody comes to lecture David and Chuck's astronomical society, intending to spy out Mr. Bass's secrets. Hardcover edition illustrated by Robert Henneberger.
Original title: Stowaway to the Mushroom Planet
Genre: Fiction→ Children & Young Adult→ Science Fiction→ Outer Space