Hayley and Jeff are out to dinner with Danuta and her new boyfriend, Marco. Marco is brilliant and won the tournament on the game show "Oo Oo I Know That."
Seeing how intelligent Marco is, Hayley starts resenting Jeff for not being clever.
Hayley learns that she is missing out on things that she wants to do due to Jeff's lack of intelligence.
Later, Hayley says Marco's name instead of Jeff's name during sex. They argue, and Hayley calls him "dumb," which causes him to storm out.
Jeff takes a walk to clear his head and runs into Stan out on a drive. Stan reveals he's collecting animals for the CIA Doctor, and Jeff joins him in the car.
Roger is at the hospital after getting bit by a snake, helping Stan get animals. He gets the bill and learns that it's so high because of the anti-venom.
Roger gets the idea to harvest venom from the Doctor after learning that he could make a boatload of money.
Stan and Jeff arrive at the C.I.A. and discuss that the Doctor is experimenting trying to increase intelligence, and Jeff wants the Doctor to do it to him.
Jeff runs into a C.I.A. agent, who tells him that a relationship with someone more intelligent than him won't last. This prompts Jeff to swiftly head down to the C.I.A. doctor to volunteer as his first human subject.
Hayley arrives before Jeff get's the procedure done, but signs on and allows Jeff to continue.
The procedure is a success, and Jeff is suddenly a smart person.
Jeff speaks French, and can create beautiful pieces of art. Danuta invites them to Johanna's lakehouse!
Roger tricked steve into hunting for venomous snakes to harvest their venom. They both get attacked by a snake, and get bitten a LOT.
At Johanna's house, Jeff impresses everyone while Hayley embarrass herself. Jeff gets angry at Hayley, and leaves her.
Hayley falls into a slump, and moves on to a worse, disgusting new boyfriend who is borderline abusive.
Danuta calls Hayley and tells her that Marco has been missing. Hayley finds out that every male winner of the game show has gone missing. Smart Jeff dismisses this info as a conspiracy theory.
Hayley drives off, and Johanna comes in and knocks Jeff out.
Roger tries to convince Steve to continue snake hunting, but Steve refuses.
Roger constantly fails at getting the venom, and it is revealed that he alone depleted the world's entire supply of anti-venom.
Jeff wakes up and he is chained up in a strange looking basement.
Johanna reveals their plan, to harvest semen of the smartest men and create a superiorly intelligent race.
Jeff pleas for his life, but it doesn't work. Suddenly Hayley bursts in, with Myron, and uses him to attack the cult members.
Hayley and Jeff hide in a closet, and they both may lose their life.
Jeff wants to be dumb again, so that he could think of something stupid to out-stupid them. He gives himself a lobotomy, and goes back to being dumb.
The stupid plan involves converting themselves in vasseline to become invisible. It works because they're slippery, not because they became invisible.
Jeff accidentally destroys the machine, which explodes the giant tank of samples.