Wacky inventor Wayne Szalinski (Rick Moranis) is at it again. Apparently shrinking his kids was not enough. This time he has inadvertently increased the size of his toddler, Adam. Electromagnetic forces — televisions, lights, and microwaves — continue to make Adam grow more and more. Unfortunately, the toddler has escaped with his “big” brother Nicky and the unsuspecting babysitter (Keri Russell), and he’s heading for Las Vegas, the neon capital of the United States. Will Mr. and Mrs. Szalinski (Marsha Strassman) make it there before Adam terrorizes the city?