The episode begins with Bill the Lab Guy showing the Action League the joys of stargazing through his telescope. The Flesh asks Bill what he and the rest of the League are looking at. Bill tells him, "The Stars", and The Flesh thinks they mean movie stars. He knocks them over and wants to look through the telescope himself. Bill starts to regret inviting the League over. When he looks through the telescope again, he sees a meteor headed towards Earth.
As the meteor heads towards Earth, Meltman, Stinky, and The Flesh make excuses to get out of saving the Earth, but The Chief tells them that they're the Earth's only hope. Bill explains his plan to the League, telling them they will be sent on a rocket to intercept the meteor and knock it off course with the really big bombs. The League likes this plan, and with no time to waste, The Chief tells the League to begin their training for space travel.
At the kitchen, Bill and The Chief put the League in a salad spinner, to simulate the gravitional effects of take-off. The Chief pulls the rope, which spins the spinner, making the League dizzy and nauseous. The spinner then falls off the kitchen shelf and crashes into a wall.
Later, the League to stands on a bullseye as Bill tells them the pressure simulator will prepare them for the extreme conditions of deep space. Stinky tells Bill the simulator looks like a sledgehammer, and Bill hits the Leauge with it. He tells them that the sledgehammer is a simulation.
Next, the League is on a slingshot. Bill is about to explain the effects of the simulator, but Stinky tells him to just get the simulation over with. The slingshot launches them onto the ceiling, and The Flesh asks if they're saving the world yet. The Narrator tells him that they aren't yet, but they will soon.
The Narrator decides to skip to the next scene, where moments later, the League is in a rocket being launched into space. Bill tells The Chief that the fate of the world is in the League's hands. The Chief asks Bill if everyone is going to die, and Bill tells him, "Yes.".
In space, the League sing while approaching the meteor. They stop when Thundergirl notices the meteor on the ship's radar. The Chief appears on the screen and tells them to arm and deploy the bombs. The League suddenly remember that they forgot to bring the bombs. The Chief angrily tells them that he asked them if they had everything before they left. The Flesh tells him they thought he meant their toothbrushes. Meltman then says that they're going to head back home, but the Chief angrily disapproves, and tells them that they're going to crash the rocket into the meteor under his orders. Meltman ignores The Chief and purposely cuts off their transmission. Stinky then tells the League that as much as he likes the people of Earth, he's not going to risk his life to save theirs, and that he's going to turn the rocket around. The rest of the League cheers, until he accidentally breaks the steering wheel, dooming them all. The Narrator asks the viewers if the Action League will crash into the meteor, then says he doesn't care about them because he doesn't Want to die, then tells the viewers to stay tuned for Part 2.
In the second act, with their rocket headed for the meteor, The Leauge reflect on the meanings of their lives. Thundergirl is upset that she never got to direct, Meltman tells the League that even though he's just a chunk of melted plastic, at least he tried, Stinky tells The League they're not such tossers after all, and The Flesh realizes he's naked. The League's rocket crashes straight down into the meteor.
Moments later, the League regain consciousness, and realize they're on the meteor. They knocked it off course and saved the Earth. Thundergirl then says that the Earth is going to give them the biggest parade when they return, but sadly, the Earth is millions of miles away from them, and they're stuck on the meteor.
Back on Earth, Bill tells The Chief not to worry, as according to his calculations, the meteor will return to the Earth's orbit in the next 100,000 years. The Chief, who is wearing a fez and holding a drink, asks Bill if he looks worried as the episode ends.
- Bill the Lab Guy: "The future of mankind is in their hands."
- The Chief: "We're all gonna die, aren't we, Bill?"
- Bill the Lab Guy: "Yes."
- The Flesh, Thundergirl, Stinky, and Meltman (singing): "The engines on the rocket go vroom vroom vroom, vroom vroom vroom, vroom vroom vroom! The engines on the rocket go vroom vroom vroom..."
- Narrator: "A planet, doomed. A rocket, kaboom."
- Bill the Lab Guy: "Don't worry, Chief, according to my calculations, the meteor will return to the Earth's orbit in another 100,000 years."
- The Chief (Wearing a fez and holding a drink): "Do I look worried?"
- Narrator: "The end."