The episode begins at Bill the Lab Guy's Secret Laboratory, where Bill is working on a formula that makes people super-big. Meltman arrives and wants to talk to Bill. Unfortunately, Bill is busy and is in no mood to talk to him. However, Meltman decides to talk to him anyway. He wishes he had a better super power, as all he can do is melt. He asks Bill if he can give him a better super power, but Bill tells him he can't, as he's too busy working on his super growth formula. Upon hearing this, Meltman drinks the super growth formula, which has a minty aftertaste. When Bill finds out, he is in shock. Meltman then grows into a giant, much to his excitement. Bill tells Meltman isn't ready, and still needs to be tested, but Meltman is too excited to care. He dances happily, inadvertently smashing Bill in the process.
At Action Headwquarters, The Chief tells The Flesh, Thundergirl, and Stinky Diver that the President will be in town next week, and he will need each of the League's super powers; The Flesh's super strength, Thundergirl's super flying power, and Stinky's super sharp shooting. When he tries to think of a job for Meltman to do, Stinky suggests that he get the donuts. The League then chants for donuts as the new giant Meltman arrives to tell them otherwise. The Flesh tries to guess what's different about Meltman, including if he got a new haircut (when he has virtually no hair). The Chief then tells The Flesh that Meltman obviously drank Bill's secret formula, and threatens to suspend Meltman. Meltman then grabs the rest of the League, and decides to suspend them himself. Suddenly, an Action Fax comes through. Meltman answers the Action Fax, telling him that there's trouble at Backyard State Park, and two kids spending a birthday party there are in danger. The Action League climbs aboard the Action Mobile, and Meltman, who wants to sit in the front seat, smashes the Action Mobile and the League inside it with his enormous size. The Chief tells Meltman that they were those kids' only hope, and now that they're smashed, they can't save them. Meltman decides that he will save the two kids by himself.
Meltman tries to catch the next bus to Backyard State Park, but unfortunately misses it. At Backyard State Park, the two kids, who are holding onto some balloons trapped in a tree, hope someone will save them. The Narrator asks the viewers if Meltman will be able to save the two kids in time, then tells them to stay tuned for Part 2.
In the second act, Meltman arrives to Backyard State Park by taxi. At first,t he kids are glad that the giant Meltman has come to save them, but Meltman accidentally gets hit by a rake, and they begin to lose hope. Meltman then trips on a tricycle and lands in a kiddie pool. However, he's not ready to give up so soon. He runs over to the tree, and tries to grab the balloons, but they are too high for him to grab, so he picks up a bench and puts it under the tree. He then climbs on the bench, and is now able to grab the balloons. He carries the balloons over to a picnic table and sets the kids down on it. The kids thank him for rescuing them. The rest of the Action League, as well as Bill the Lab Guy, arrive on a skateboard and congratulate Meltman for saving the kids. Meltman decides that now that he's a giant, he should get a mega salary increase, as well as a mega apology from the rest of them. Bill then tries to tell Meltman something important, but Meltman interrupts him, letting his new super size go to his head. Suddenly, Meltman shrinks back to his normal size, and the two balloons he's been holding on to the entire time carry him away. What Bill was trying to tell him earlier is that his formula's effects are only temporary. The Flesh then jokes that Meltman got his raise, and Thundergirl says she's gonna miss Meltman. Stinky agrees with her. After all, who's gonna get them donuts? They all laugh as the episode ends.
- The Chief: "Okay, you guys, listen up, The president's in town next week. Thundergirl, I'm gonna need your super flying power, Flesh, your super strength, Stinky, your super sharp shooting. As for Meltman... Uh... Um... Well, uh..."
- Stinky Diver: "He can get the donuts!"
- The Flesh, Thundergirl, and Stinky Diver: "Donuts! Donuts! Donuts!" (they all laugh)
- The Flesh: "Gollers, Melty, you look different! Did you get a haircut?"
- The Chief: "No, you moron! He obviously drank Bill's secret formula. Meltman, you're suspended!"
- Meltman: "Oh, contraire, Chiefster..." (He grabs the Action League) "...you're suspended. All of you are, in the air!"
- The Flesh, Thundergirl, Stinky Diver, and The Chief (boarding the Action Mobile): "Action League away!"
- Meltman: "I've got frontsies!"
- (Meltman jumps on the Action Mobile, smashing it)
- Stinky Diver: "Ow!"
- The Chief: "My spine!"
- The Flesh: "Ouchies!"
- Meltman: "Man, this car has zero leg room."
- Narrator: "Meltman, enlarged. Kids, ensnared. The League, en... smashed!"
- Meltman: "Mega Meltman, with the power to climb on a bench!"