This is the fourth Edition of The Adventures of Billy & Willie and the magic cave-Titled (Space Travel on Galactic Express). Beaver the time keeper along with Billy, Willie, and friends go on a magical adventure into space to visit old friends and discover new friends as well. During their journey they find themselves on zombie planet saving captured alien friends and getting into battle with small and giant zombies. They also visit multiple planets and play a variety of games with aliens from different planets around the universe.