In Wyoming, months after Henry and Sam's deaths, Joel tells Ellie about his brother Tommy joining and quitting the Fireflies, and how they got separated on bad terms. She wonders if he will help them, to which Joel responds "I guess we'll find out". They go past a dam, and encounter a small grave with a teddy bear on it, that makes Ellie think about Sam and his robot toy. Joel refuses to talk about it, and tell her to just move on with her life. They eventually reach the closed gate of a power plant, and are held at gunpoint by several people. Tommy is among them, and greets his brother with a hug. He introduces them to Maria, his wife, who along with her father is in charge of a self sustained settlement of people, and are using the power plant for electricity. As he shows Joel around, Tommy says he went back to Texas a few months back, and tries to give Joel a picture of him and Sarah together he found at his house, but Joel refuses. The brothers later witness the workers getting the power generator up and running again.
In private, Joel tells Tommy about Ellie's immunity and asks him to bring her to the Fireflies, which Tommy refuses, since he is now responsible for all the people of his community. Angered, Joel shoves him and calls him ungrateful for all the years he kept the two alive, but Tommy replies that he "got nothing but nightmares from those years". As he says this, the plant is attacked by looters, and Joel is forced to help Tommy fight them. After eliminating the bandits, Tommy (seeing Joel and Ellie interact) agrees to take her, but Ellie, suspecting that Joel is going to leave her, steals one of their horses and runs off into the woods.

After fighting more bandits, Joel and Tommy track her down to an abandoned ranch house, where Ellie confronts him about dumping her on Tommy. She brings up Sarah, saying that she is not his daughter and they are doing fine together, which just seems to confirm his decision. More bandits arrive at the ranch house and the brothers manage to kill them all. However, as they are heading back, Joel has a change of heart and decides to go with her himself. Tommy informs them that the Fireflies are in the Science Building of the University of Eastern Colorado, and Joel bids him goodbye.