"Zack is headed back to Earth for the first time since moving to Nebulon. He can't wait to see Bert and show his new friend, the former bully Seth Stevens, all around his old stomping grounds. When Zach's dog Luna escapes and goes missing, sightseeing plans take an unexpected turn. Will Zack find Luna before he has to head home to Nebulon?--

When a cosmic storm hits, stranding the Nelsons on their new home planet, Nebulon, Zack's hopes of a white Christmas in Vermont are dashed, but Nebulon provides a surprising alternative.

Zack is shocked to find a large, green, six-eyed creature sitting in his place at school one morning, but soon learns that he and the "monster" have a lot in common.

Although Halloween is not celebrated on the planet Nebulon, Zach, a boy from Earth, discovers that ghosts may be real.

Will troublesome cabin mates ruin Zack's summer at space camp on the planet Sylvan?

Zack and his father are invited to join the Nebulon Navigators as they set out to return a lost baby pterosaur to the Prehistoric Planet, where Zack sees animals and plants he had only read about in books.

Zack and Drake venture to Gluco, the candy planet, for some Easter fun but while competing in such activities as an egg toss and a three-legged race, Zack is so determined to come in first that he considers cheating to win.