Puggy and Mannie are back in their last adventure to take on the aliens once and for all. At the beginning of the series in "A Suspicious Neighbor," Puggy first made contact with an alien who had moved in next door to him. This alien, Cyze, had captured animals to experiment on so that he could control them to do whatever he asked of them. A new alien was introduced in "Cat's Revenge" as Zork, who had taken up residence at a blue house a few blocks from Puggy to help Cyze with the experiments on the animals. In book one, due to fate, Puggy was modified with advanced technology which led him to become a spy. Saving Mannie, his Jack Russel friend, in book one, Mannie begins showing his true worth and after becoming modified in book two, Mannie is now a key player in "The Aliens Invasion". In "The Aliens Invasion," the aliens were not easy to find this time because they had left the blue house and disguised themselves as humans. To make matters worse, they had figured out how to control the animals completely! Puggy and Mannie knew that they wouldn't stand a chance against the animals so they needed a plan that involved not fighting the animals but having the animals fight for them. But what's this? Puggy appears to have come down with a dreadful illness and is unable to perform to the best of his abilities. It seems like after this everything started to go downhill fast and more problems started to arise. It was up to Mannie now to try to save the day while Puggy was on the sideline giving the animals instructions on what was needed to be done.