Wayne Szalinski is at it again. But instead of shrinking things, he tries to make a machine that can make things grow. As in the first one, his machine isn't quite accurate. But when he brings Nick & his toddler son Adam to see his invention, the machine unexpectedly starts working. And when Adam comes right up to the machine, he gets zapped along with his stuffed bunny. The Szalinski family is back, this time hilarious disaster strikes when an experiment causes their new toddler son to grow many stories tall.