While researching a paper about George Washington Carver in celebration of Black History Month, Steve uncovers a conspiracy that's been going on since the Civil War. When the curator of the Smithsonian Peanut Museum reaches out to tell Steve the truth, he's mysteriously murdered, and Steve and Stan are tracked by a secret society that will stop at nothing to keep this scandalous secret of American history.

Stan hunts for an ex-KGB agent but can't find him--until he moves in next door. And Steve is building a rocket for a school science project, but can't get it to work--until he gets some help from his new next-door neighbor. Meanwhile, Roger and Klaus head off on a European vacation.

After outing himself as an alien, Roger (in disguise) finagles his way into being appointed the CIA's chief alien hunter to take advantage of a lavish expense account--while coming up just short in attempts to catch himself. Meanwhile, Francine shocks her family by displaying a prejudice they never knew she had.

When Langley Falls bans trans fats, Stan and Steve become smugglers. Meanwhile, Klaus gets word that he has received an inheritance but can't collect it because the CIA has turned him into a fish.

Steve and his friends sabotage a stuck-up kid's bar mitzvah after the kid hits on Steve's girlfriend, Debbie. But when Snot is wrongly accused of stealing the kid's bar-mitzvah money, his own bar mitzvah is put in jeopardy.

Roger declares that he was sent to Earth to be "the decider" of humanity's fate, and Stan challenges him on it.

Stan puts down liberal social programs because he thinks they are a waste of money and gives Francine a hard time for lending a helping hand at the local homeless shelter. When Stan develops a nasty addiction and needs help, he suddenly has a change of heart.

Stan and Francine have trouble keeping up with a younger couple's lifestyle.

After Snot professes his love for Hayley and gets shot down, Steve and Roger devise a plan to cheer him up. Roger dresses up as Steve’s cousin from New Jersey, Jenny Fromdabloc, and Snot falls hard for her. Meanwhile, Stan wants to live like a gentleman of the 1960s, complete with dark suits and dry martinis.

Stan joins Roger and Steve's fictional detective agency, but he ruins the fun by being extremely incompetent at his "job." Roger demands that Steve fire Stan, but Steve cannot bring himself to do it and ends up lying to Roger. Things take a turn for the worse when Stan is kidnapped, and Steve must tell Roger the truth.

The Smiths get drunk at Roger's Mardi Gras party and make a pact with Bullock; Roger tries to find the person who left a pastie in the attic.