A New Planet — A.I. Newton

In the eighth book of the Alien Next Door series, Harris and Roxy have stowed away aboard Zeke's spaceship and are flying to his home planet of Tragas!

Harris and Roxy have hidden away on Zeke's family's spaceship and are headed to Tragas! Zeke's parents freak out when they discover the kids aboard, but they've come too far to turn back. So that gives Harris and Roxy two whole days to explore the alien planet with Zeke while the ship refuels before they all have to fly back to Earth. But, much like Zeke had to on Earth, they have to blend in. Will they be able to hide the fact that they're the aliens on this new planet?