Episode 5 goes deeper into her story, revealing that Kathleen's motivation for finding Henry is because he ratted out her brother to FEDRA, resulting in his death.

Source: https://www.cbr.com/the-last-of-us-twd-lesson/

First encountered in season 1, episode 4, was the leader of a resistance group who’d succeeded in ridding Kansas City of the oppressive FEDRA.

Source: https://screenrant.com/last-of-us-kathleen-origin-story-melanie-lynskey-response/

In the game, we know that the hunters of Pittsburgh have effectively liberated the city from the local FEDRA branch, which was a cruel and oppressive institution, denying people rations and brutally keeping citizens in line.

Source: https://kotaku.com/last-of-us-hbo-tlou-ep-four-s1e4-recap-joel-kansas-city-1850077722

She continued: ‘I’m playing a person who meticulously planned & executed an overthrow of FEDRA.

Source: https://metro.co.uk/2023/02/09/the-last-of-us-actor-melanie-lynskey-hits-back-at-body-shamer-18252308/

The moral dilemma created by Henry's collaboration with FEDRA is a central theme in episode 5, and the extra complication of Sam being deaf makes it even thornier because of how reliant it makes Sam on Henry.

Source: https://screenrant.com/is-sam-deaf-in-last-of-us-game/

They bring him into the city, which establishes that FEDRA doesn't shoot strangers on sight, but has a protocol for dealing with newcomers.

Source: https://www.cbr.com/the-last-of-us-premiere-importance/

This is new for the show, and makes it that much more clear why Riley wants a life outside of what FEDRA has in store for her.

Source: https://kotaku.com/last-of-us-tlou-s1e7-left-behind-ellie-riley-hbo-mall-1850161819

We then leave Joel and Ellie and meet Kathleen (), who is interrogating an older man in a FEDRA lockup, asking him where she can find the people she's looking for.

Source: https://collider.com/the-last-of-us-episode-4-recap-please-hold-my-hand/