James is a literature graduate student driving to his friends’ house in Colorado with his girlfriend, Molly. Recently, Molly was laid off, which worries James because he won’t be able to sustain them both with his meager graduate student salary. Although she’s smart, she’s too sensitive, and he feels like this will keep her from getting another job. As they drive, they pass a swarm of butterflies. The only way to get through is to keep driving, which means killing the butterflies. Although Molly begs James to stop, he says that he can’t because they’re in the middle of the highway. Their car is covered with the bodies of dead butterflies. The couple arrives at their friends, Sam and Jenny’s, home in Denver. Sam and Jenny have three kids. Sam invites James to come to the city with him the following day, but James declines. Molly tags along with Sam because she wants to see a friend of hers. Alone, James talks with Jenny, who reveals that Sam killed someone in a hit-and-run. James realizes that his friends’ marriage is going to fall apart, and he’s gutted. As he sits with Jenny, he waits for Molly to return with Sam, but they spend the whole night out. James becomes convinced that Molly and Sam are sleeping together, so he resolves to break up with her. He’s sick of being jealous and no longer wants to take care of her. That night, Jenny and James sleep together. When Molly and Sam come back the next morning, Molly pulls James aside and says that Sam’s crazy. James realizes that Molly didn’t sleep with Sam, and he feels regret instantly. Later that day, Molly steps out of the shower, wearing Jenny’s underwear. She comments that she doesn’t remember purchasing that pair. James says he also doesn’t remember where she got those from. She says, “Oh well,” and leaves to go to a coffee shop to work on her play.