Five years after the events in Salt Lake City, a now 19-year-old Ellie makes a discovery while on patrol with her best friend Dina. Back in Jackson Hole, Joel seeks help to mend his relationship with Ellie.

As a storm brews in the mountains, the people of Jackson Hole prepare for the worst amid increased sightings of Infected. Meanwhile, Abby weighs her options.

After Dina shares crucial information, Ellie prepares to petition the town council, even while she struggles with her deep emotional scars. On the outskirts of Seattle, a religious sect attempts to flee a war – raising questions on what lies ahead.