Local horticulture enthusiast, Dr. Dandelion, engineers a Stink Monster odorous enough to force all the residents out of town. Even worse, the smell causes Alex to lose his grove. The Superheroes must find a way to defeat the ever-growing Stink Monster before it turns Greenville into Stinkville. Together, Megablast has to find a way to drive the stink out of town while learning that believing in each other is the best way to save the day.