In the aftermath of the loss of Tess (Anna Torv) in the previous episode, Joel and Ellie are now only 10 miles from Boston. Joel is ignoring Ellie until she points out that they needed her and no one forced them to accompany her, so Joel shouldn't blame her for the death of Tess. Joel nods silently, seemingly accepting her argument. Ellie asks how far they have to go to reach Bill (Nick Offerman) and Frank (Murray Bartlett), and Joel says it's a 5-hour walk.
During the journey, Ellie asks about Joel's scar near his temple, and Joel explains that he was shot at and missed, then shot back and missed as well. When Ellie suggests she should carry a gun, Joel immediately dismisses the idea. They come across an abandoned gas station where Joel says he stored some items. As Joel searches, Ellie tells him about a friend of hers who liked Mortal Kombat and goes exploring on her own. Ellie discovers a basement with an infected trapped under rubble, uses her switchblade to cut open its head before killing it. Joel finds his stash and leaves his gun without ammo, while Ellie keeps the basement encounter to herself.
As they proceed, they come across a crashed airplane and Ellie enquires about the cause of the world's destruction known as "Outbreak Day". Joel explains that no one knows the exact cause, but it's believed that mutated cordyceps entered the food supply through an ingredient like flour or sugar, infecting those who consumed enough. With the infected food reaching stores globally, the outbreak spread rapidly, leading to the world's downfall.
Joel tries to steer them away from something he doesn't want Ellie to see, but she is curious and heads towards it. She finds a pile of human bones, some with luggage nearby. Joel tells her that a week after the outbreak, soldiers evacuated small towns by promising to take them to a quarantine zone. However, if there was no room, they killed those who were likely not infected and left them there. When Ellie asks why, Joel states "dead people can't get infected".
The episode flashes back to a town being evacuated by soldiers on September 30, 2003. As people are loaded into trucks, we see a house with multiple cameras and a man watching the evacuation from his basement. He grabs his gun when soldiers come near, but they don't find him. The man is revealed to be a doomsday prepper with a basement full of guns and supplies. He emerges after the soldiers leave, wearing a gas mask and carrying weapons. This is the introduction of Bill.
Bill has been preparing for the outbreak and makes the most of it by stealing gas, supplies from a Home Depot, power from a natural gas plant, wine from a winery, and running his own generator. He fortifies the town's fence, grows his own food and animals, and has cameras set up to keep watch. As he enjoys a well-prepared dinner, he monitors the town through his cameras and the traps he's set up to keep the infected out.
In 2007, Bill is still thriving on his own in his town when he receives a notification about something stuck in a hole outside his fence. When he investigates, he cocks his gun, and the person inside states that he's not infected or armed. The stranger says he was headed to Boston with a group of ten people but is the only one left and came from the now gone Baltimore QZ. After checking for infection with a device, Bill points the man towards Boston but agrees to feed him after hearing he hasn't eaten in two days. Frank introduces himself, and Bill brings him to his home.
Frank takes a shower and changes into fresh clothes, and Bill prepares a meal. Frank is grateful and can't believe such fine dining is still possible in the world. Over dinner, Bill pours wine and they bond over Linda Ronstadt songs. After dinner, Frank goes to a piano and finds a collection of Linda Ronstadt songs, which he believes belong to Bill. Frank plays the wrong notes and sings off-key, and Bill stops him, playing the song correctly. Frank is moved by Bill's performance and kisses him, leading to intimacy between the two. Frank says he'll stay a few more days, which Bill agrees to. They gently hold each other, kissing softly, and a moment of intimacy that they likely never imagined in the current state of the world.
Three years later, Frank wants to improve their street by painting the house and fixing up some shops. Bill questions if they'll host formal garden parties and Frank says no, but they will have friends over. Bill thinks they have no friends and Frank mentions a woman he's talking to on the radio. This woman is Tess, who comes to their house for dinner with Joel. Bill is uncomfortable with strangers and keeps his gun on the table. Frank and Tess plan to work together in the future and Joel offers to help Bill and Frank with supplies from the QZ. Bill refuses, but Joel points out the faults in his fence. After Tess and Joel leave, Frank suggests they have a radio code. Joel warns Bill that raiders will come, but Bill says they'll be fine.
Three more years later, Bill has fortified his fence even more, and Frank surprises him with a strawberry garden. Bill is overjoyed and apologizes for getting older faster. The two kiss and express their love for each other. During a rainy night, raiders attack and Bill's traps catch some of them on fire. Frank saves Bill after he's shot and tends to his bullet wound. Thinking it's the end, Bill tells Frank to call Joel but Frank says he's not alone because Bill is with him. This is their first moment of danger together and Frank takes the initiative to save Bill's life.
Cutting to a decade later, Frank and Bill have both visibly aged. Frank is now in a wheelchair, struggling with sickness and unable to finish his latest painting—a portrait of Bill. During dinner, we see Frank relying on a liquid diet and medication, with Bill having to help him to bed at night. The following morning, Frank has made his way to his wheelchair, though it took him most of the night to get there. This frustrates Bill, who thinks Frank will fall asleep in the chair, but Frank declares this to be his last day and intends to stay awake. As they sit together, Bill becomes emotional and asks about finding a doctor, to which Frank responds that no cure for his illness existed before the world ended.
With tears in their eyes, Frank recounts all the good days he's had with Bill and asks for one more. He wants Bill to make him toast, go shopping for outfits with him, and then get married. Frank requests Bill cook dinner, crush his pills, and put them in his wine. Frank wants to fall asleep in Bill's arms after taking the pills. When Bill hesitates, Frank asks if he loves him and if he can "love me the way I want you to." The two spend a touching day together, exchanging rings and vows, enjoying their last meal together and drinking the same wine from their first meal. At the end of dinner, Bill prepares two glasses of wine with enough pills to put Frank to sleep, when Frank realizes Bill has put the crushed-up medication in his own wine too. Bill doesn't see it as a sad suicide, as he's old, content, and Frank was his purpose. Frank finds the act incredibly romantic, and they head to bed for their final moments together.
Later on, Joel and Ellie arrive at Bill and Frank's place. They find the flowers wilting, the front door unlocked, and the remains of their last meal on the table, coated in dust. Joel investigates and finds the bedroom barricaded, while Ellie discovers a letter from Bill with a car key on top, addressed to "To Whoever But Probably Joel." Ellie reads the letter, which warns whoever finds it not to enter the bedroom. Bill writes that he respected Joel despite never liking him, and that he saved someone worth saving, and that Joel should use his weapons to protect Tess. Upon reading the letter, Joel reads the part about protecting Tess and crumples the paper up.
In the garage, Joel finds Bill's truck but discovers there's no battery. He retrieves the ingredients for a battery from the fridge and returns to the house, where he asks to see Ellie's arm, which still hasn't changed. Joel decides to head to Wyoming to find his brother Tommy, who is in trouble, and tells Ellie if she's coming with him, there are rules she must follow: she can't mention Tess, they have to keep their histories to themselves, she can't tell anyone about her "condition," and she must do what Joel says. Ellie agrees, and they grab what they can, but Joel denies Ellie's request for a gun. Ellie finds another gun and hides it in her bag. They get into Bill's truck, where Ellie discovers a Linda Ronstadt cassette, and the two depart for Wyoming.
