Gabby gets a history lesson when alien technology delivers a boy from 1821 to modern-day Havensburg. Gabby recruits her alien friend Rooney to help get him home.
With the Congressional Fitness Test coming up, Gabby dreads her least favorite physical activity-running. She devises a plan to get out of it that causes mayhem for Swift.
When Grandma Ruth babysits Gabby and Olivia for the weekend, Gabby tries to pep her up with an alien energy drink but accidentally transforms Grandma into a Gwargwarian warrior.
Unaware of its significance, Gabby sells a cherished family heirloom. While getting it back, she realizes that she should take a more active interest in her family history.
Gabby becomes obsessed with exposing and turning the tables on Havensburg's "Fright Master," an unknown entity that terrorizes the school every Halloween.
Jeremy's friend Ziggy comes for a visit. The two aliens always cause a commotion when they get together and Gabby's planned relaxation time comes under threat.