After drinking an unfinished chemical in Bill the Lab Guy’s laboratory, Meltman suddenly turns into a giant. Changing his name to Mega Meltman, he soon finds out that his large stature is making things harder for himself and the rest of the Action League to cope with. However, in the end, this increase in size may help out a group of young kids who are trapped on top of a large tree. Near the end of the episode, Bill the Lab Guy wanted to tell Meltman that the drug was temporary. However, Meltman refused to listen and he shrunk, causing him to fly away.