Bart and Lisa ask about the attic but Homer deflects.

Bart and Lisa sneak into the attic to find the secret.

Homer and Marge reveal a creature named Hugo escaped.

Homer and Marge confess Bart has an evil twin brother named Hugo.

Hugo reveals himself and tries to sew Bart back to him.

Hugo shows his scar is on the wrong side, revealing Bart is the evil twin.

Hugo is accepted by the family while Bart is punished.

Lisa finds tiny people growing in her science project.

Lisa watches her micro beings evolve through history.

Bart repeatedly destroys Lisa's micro city with his finger.

Lisa uses a debigulator to shrink and enter the micro world.

The micro beings ask Lisa to save them from Bart, the devil.

Bart wins the science fair for creating the micro universe.

Homer is fishing when aliens Kang and Kodos abduct him.

Kang and Kodos kidnap Bob Dole and duplicate him.

Kang and Kodos impersonate Clinton and Dole on TV.

Kang and Kodos campaign with absurd promises.

Homer frees the real Clinton and Dole from the spaceship.

Homer accidentally traps the real candidates again.

Kang and Kodos win the election and take over.

Kang becomes president and forces humans to build a ray gun.

The episode ends with credits and a scream.