Zack's back at work again, as an Alien Agent. His assignment: find an alien kid who hijacked a spaceship to Roswell, New Mexico. Sound easy? Not quite. Because Zack's dad is going too. And he's being chased by a man with a serious grudge against aliens. Can Zack find the missing alien and keep the truth from his dad while escaping the clutches of one Major Garrett? It's all in a day's work for Earth's Alien Agent.