A Star Wars-style text crawl explains how a resistance force led by Princess Serina has stolen vital radio transmissions from an evil Galactic Alliance. The Darth Vader-like villain, Lord Buckethead (named only in the closing credits), pursues Serina, but, due to an error in navigation, instead lands on Earth.
Lord Buckethead then leads his Jawa-like minions into the nearby suburb while none-the-wiser of his blunder. He immediately mistakes town folk such as Chester, the local baker, for a galactic hero called Captain Starfighter; and again later Karen, an employee at a local transmission repair shop, for Princess Serina, promptly abducting her for interrogation.
Max, a timid exterminator aspiring to pass a crucial exam for a shot at executive promotion, inadvertently finds himself at the scene and aids Karen in escaping. The duo makes a hasty retreat into the woods, only to be captured and brought aboard the aliens' ship.
The minions eventually realize that they have erred, and arrived on the wrong planet. Unfortunately, attempts to convey this to the arrogant Lord Buckethead are met with harsh consequences due to his intolerance for insubordination, often resulting in execution.
Despite the setbacks, Max and Karen manage to escape once more. After a chaotic adventure in a superstore, they eventually arrive just in time for Max's important exam. However, their respite is short-lived as Lord Buckethead arrives, seizing Karen and demanding the coveted radio transmissions. Failure to comply would mean the destruction of the entire town.
The military arrives but is easily pushed back by the spaceship's superior defenses. Max meanwhile takes the opportunity to sneak aboard Buckethead's ship and rescue Karen. The two make it off just as the ship is preparing for lift-off. Lord Buckethead's minions meanwhile have had all they can take from his arrogance and bullying abuse, and literally kick him off the ship as he stands on the main boarding ramp, marooning him on Earth.
He then pursues and corners Max and Karen, but is killed by Chester, who appears in a Superman style outfit, revealing that he actually is Captain Starfighter. The film finally ends with the alien spaceship flying away from Earth.
^"The Latest: Costumed candidates in UK get moment of fame". WNWS-FM. Associated Press. June 9, 2017. Retrieved June 9, 2017. She looked grim as her local victory was announced, even while sharing a stage with a man dressed as the Muppet character Elmo (he got three votes), Howling "Laud" Hope of the Monster Raving Loony Party (119 votes) and Lord Buckethead, a towering figure in black with a pail on his head (a resounding 249 votes).
