The planet Jupiter is days from destruction. Over the radio, the president urges calm and threatens military force against looters. Crossing Indiana and Illinois, Don and Rodney hit gridlock on a four-lane highway caused by a jackknifed trailer. While Rodney is outside gathering information, a man in a truck deliberately rams the car ahead of him, and that car’s owner draws a pistol and opens fire. Rodney scrambles back into the RV and drives off-road through a ditch to escape. They later discover a bullet hole near the bumper. Don wants to call the police, but Rodney refuses, citing Pantomime’s warning that authorities are killing civilians. Rodney acknowledges that turning back is not possible: They made a promise to someone, identified only as “him,” and must keep going.

In South Dakota, sheltering from a storm at an abandoned gas station, Don breaks down over the idea that he might never taste another apple. Rodney holds him until he eventually calms down. They steady themselves by imagining trips to Italy they will never take. They also route around Minnesota to avoid encountering John and Megan.

On a wet road, they find a teenage girl lying on the pavement, wearing a yellow dress and sporting a black eye. She tells them her name is Amelia and asks for a ride home, Speaking in a flat monotone that suggests dissociation, she recounts a brief romance with a boy named Chris who died in a highway crash. She describes humanity as being herded toward suffering like the cows on her family’s ranch being led to slaughter. As they approach the ranch, she reveals that she shot seven ranch hands, both her parents, and a visiting family of three to spare them the pain of the apocalypse. She produces a loaded gun from her pocket and offers to kill Don and Rodney as well, framing it as mercy. Rodney declines and he and Don coax her out of the car. Back on the road, the couple debates whether they could have helped her. Don compares Amelia’s disassociation to Jeremy’s, drawing a parallel to their son’s own retreat and death. Rodney insists they have to keep going to honor the promise.

Entering Montana, Don and Rodney hear a presidential address delivered from an undisclosed location. The president confesses doubt in his faith, admits to starting wars, and pleads with civilians not to riot. The planet Jupiter is gone, and perhaps 10 to 15 days remain before the black hole consumes the earth. The promise they made to Jeremy takes on new weight for Rodney, who insists that he and Don built their life together through their own choices rather than destiny, and that finishing the trip is their responsibility alone. Rodney resists Don’s comparison of Jeremy to Amelia.

At Swan Lake, the couple meets Amy and Becca, a young lesbian couple who fled Amy’s evangelical Texas family to build a life together. Amy’s father had subjected her to a lengthy prayer session at their church in which she forcibly held down as the elders tried to cast the devil out of her to change her sexual orientation. The four connect as queer people of different generations. Rodney gives an account of LGBTQIA+ history, telling them about The 1967 Black Cat Tavern raid in Los Angeles (a pre-Stonewall police raid on a gay bar). He explains that Pride started in Tucson, Arizona, as a result of the murder of Richard Heakin, who was beaten to death by four teenagers outside a gay bar. He describes the murder of 21-year-old Matthew Shepard in Laramie, Wyoming, and the AIDS epidemic, naming friends he lost to the disease while the Reagan administration ignored the crisis. 

That night, the campground holds a communal nude swim in the glacial lake. Don and Rodney undress, wade in, and kiss underwater. Back in the RV, they are intimate for the first time on the trip as a way to be fully present despite the global turmoil. At dawn, Amy and Becca knock on their RV with news: Mars is gone, and Earth’s moon is next.