Homer, Lisa and Bart get tickets for the latest chapter of "Cosmic Wars". The movie wasn't what they hoped it would be, and Marge suggests that the kids write a letter expressing their dissatisfaction to creator Randall Curtis. Two weeks later when they get a stock letter in reply and they ask if they can go to the "Cosmic Wars Ranch" and complain in person. The family goes to Northern California. While Marge and Homer go on a winery tour, Bart and Lisa go to the ranch to find the creator and make their feelings known.
After Bart and Lisa have their meeting with Curtis they rejoin their parents, who they find are both drunk on free samples they had at the winery. Marge and Homer are really enjoying their wine together, but following one their nights of drinking Marge finds her with a hangover. They agree that she can stop drinking and they can still have fun together.
They go to Oktoberfest and Marge almost gets away with not drinking, but drink she does and they both leave the drunk, with Homer driving. After he drives their car off the road, Homer decides to make it look like Marge (who is passed out) was behind the wheel. The police arrest Marge; Homer is nowhere to be found at the time and he later bails her out. Barney suggests a rehab clinic for Marge to start attending. Homer finds out that Marge is going to be gone for a month, he asks Flanders to watch the kids while he goes to break her out of rehab. He finds her and confesses his guilt, which makes her angry and she starts drinking again. After some heavy drinking, Marge realizes that it isn't drinking that she liked; it was being together with Homer. She gets Homer and together they leave, after Homer promises to cut out drinking all clear liquors.