Contains spoilers for this episode.
A flashback to Jakarta follows mycology professor Ibu Ratna as officials ask her to examine a fungus linked to the first infections. After seeing the danger, she urges the government to bomb the city. In Boston, Joel, Tess and Ellie continue toward the Firefly meeting point. Joel doubts Ellie’s claim that she is immune, while Tess learns Ellie is meant to reach doctors who hope to use her condition in a cure effort. Their route takes them through flooded, overgrown streets and a hotel where a collapsed floor forces them to find another way through.
At a museum, the trio encounters infected whose advanced stage makes them clickers; the creatures’ sound and speed turn the escape into a close fight. Ellie is bitten again, but her wound begins to heal. Tess, however, has been bitten on the neck. The group reaches the State House and finds the Fireflies dead, with signs that an infected person attacked them. Tess accepts that she will turn and tells Joel to take Ellie west to Bill and Frank. When an infected horde approaches, she stays behind, spills fuel and grenades, and lights them as the creatures close in. Joel pulls Ellie away from the explosion.