The episode begins with a flashback to five years ago. A mailman named Gary connects with a man named Ennis while playing online video games. Ennis is consumed by the idea of an impending apocalypse and believes they should devise a survival plan. Ennis starts communicating with others like him and Gary - lone wolves without families or friends - who possess essential skills for survival, such as carpentry, gardening, and healthcare. Meanwhile, Gary realizes his post office has an underground shelter and begins stockpiling it with various supplies.
When the day finally arrives, Gary picks up Ennis, who turns out to be an Indian man named Ravi. He also picks up Bean, a young boy he met on his work route whose drug-addicted parents were too far gone to help him. As they stop to buy eggs, an accident occurs on the street. Teri is there, saying goodbye to Xavier on the phone. Suddenly, an EMP cuts the call and fries all electronics in the area. Gary and Ennis allow Teri to join them.
In the present, Xavier holds Gary at gunpoint and demands to know what happened. Gary explains that Teri has been staying with him and the others for three years, but a group of armed men came 12 days ago and took her and all the others.
In the past, Teri and the group gather in the post office shelter as per Ennis' plan. Gary explains that they need to stay inside for 21 days to avoid radiation and live in the post office for 3-5 years until things get better outside. Teri is naturally worried about her family, and Gary promises to help her reunite with them eventually. But for now, he asks her to help at the shelter since Ennis doesn't contribute much.
In the present, Gary takes Xavier to a location filled with people, including 16 armed men and women who seem to be guarding something. Gary says these are the people who took Teri.
In the past, Teri and the others settle into their new lives and even celebrate Christmas using unsent packages in the post office. Gary builds Teri a radio, which she uses to try and contact Xavier. She's thrilled and he leans in for a kiss, but she makes it clear that she doesn't feel that way.
In the three years that pass, Teri keeps sending messages on the radio. Jackie, a mechanic, and Crystal, a nurse, fall in love and get engaged. One day, Teri notices that Ennis has broken her radio, though he pretends he wasn't the one who did it.
Currently, Gary is narrating this tale to Xavier, who is now constructing a bomb with the intention of using it as a diversion to breach through the armed individuals and rescue Teri. In the past, Jackie and Crystal made the decision to relocate. They've encountered other groups on the outside, and Crystal has plans to establish a clinic to aid those in need. Meanwhile, Teri has been crafting biodiesel from mold - a fuel that will enable her to travel to Colorado.
At present, Gary leads Xavier to a convention where people are holding an auction. He's searching for a battery to remotely detonate his bomb. There, they encounter Jackie and Crystal, who assist Xavier in acquiring the battery and also agree to take care of Annie's infant while he pursues Teri.
In the past, Ennis speaks with Teri and apologizes for the radio incident. He states that he doesn't necessarily have feelings for her but respects her. When Bean notices a train approaching, Gary and Ennis investigate. They discover a group of individuals heading west to join Link's group, bound for Colorado!
On their return to the shelter, Ennis informs Gary to brace himself as Teri is likely to want to join that train to Colorado. In a sudden impulse, Gary shoots Ennis with his gun, causing the latter to fall.
At present, Xavier tells Gary that he knows he's keeping something hidden. Gary confesses that he was in love with Teri and will do everything in his power to reunite her with her husband. They shake hands on it.
