Phil heads to Tucson to find his brother, Mike, driving a Delorean (a la Back to the Future) there. When he gets to his family home, Mike is in bed, faking being dead. Mike is upset that Phil ignored his wishes and came to find him anyway.

The group finishes off the last of the cheese. They all feel guilty for kicking Mike out, thinking they might have overreacted -- except for Melissa, who ruthlessly insists she'd kick out anyone who started coughing up blood. The group hears the baby calf mooing and goes outside to see what's wrong. They spot the drone that Gail saw earlier, realizing she didn't imagine it.

Phil and Mike go through their attic, looking at their old stuff. Phil finds an old jar that he farted into, insistent that it's an important scientific experiment to see whether a fart can retain its smell for 30 years. Mike farts at the same time, ruining Phil's experiment. Mike passes out suddenly.

The group watches the drone, wondering who is flying it. Gail starts drinking again, now knowing that she didn't hallucinate the drone. Meanwhile, Carol tries to get the baby calf to take the bottle but it refuses. As the drone comes around again, Gail, Erica, Todd, and Carol hold up signs explaining that they're friendly. Melissa shoots down the drone, angering everyone, explaining that if the people controlling it were nice and non-threatening, they'd have stopped by in person.

Phil sits with Mike as he sleeps. When Mike wakes up, Phil pretends to have coughed up blood himself by putting sriracha on his hand. Mike asks him to stop with the pranks, no longer feeling like joking around. Phil is continually in denial about Mike's condition and Mike yells at Phil for everything being a joke to him. Phil confesses that he actually hates the haircut Mike gave him. Mike offers to help him fix it and shaves the other half of Phil's face and head for him. Mike harshly tells Phil to leave, yelling at him angrily about being a childish, selfish person and having had no life. Phil, upset, leaves.

Mike later goes to find Phil and finds him in front of the graves of their parents and the grave he dug for Mike. Mike apologizes to Phil and congratulates him for having re-started civilization by bringing all of the survivors together with his signs. Mike tells Phil that it's his dying wish for Phil to go back to Malibu, so he doesn't have to bury Mike all over again.

Melissa, sleeping on the couch with a shotgun, jolts awake and shoots at Carol when she hears Carol bringing the cow around. Everyone comes running and accuses Melissa of being slightly unhinged. She rants about the dangerous world they live in but Carol talks her down and she apologizes. They put her in the stockade as punishment for nearly shooting Carol.

Phil packs up his Delorean and leaves Mike in Tucson. Mike gives him a fart in a Gatorade bottle to replace the one that Phil wasted earlier. In exchange, Phil gives Mike his ball friends to keep him company in his solitude.

Upon returning home, Carol comforts Phil, who is upset over having left Mike. Phil successfully feeds the baby cow without even trying. Gail spots a boat outside and calls everyone over. Phil looks through the binoculars and sees the crazy boat man who Mike encountered upon first arriving on earth, who is accompanied by two men, all wielding automatic weapons. They head to shore.