How did The Last of Us change Ellie and Riley from the video game?

The Last of Us returned with another ringer this week. “Left Behind” delved into Ellie’s past, revealing how she and her best friend/first love Riley were bitten by an infected during a fateful night at an abandoned mall. Beyond just being an excellent hour of television, “Left Behind” was also an excellent adaptation of the “Left Behind” expansion to Naughty Dog’s The Last of Us video game. Let’s break down how.

As always, there will be SPOILERS for the latest episode of The Last of Us ahead, as well as for the games.

Does Ellie save Joel in The Last of Us games?

Unlike most of the series, this episode doesn’t draw directly on 2013’s The Last of Us game, but rather on a standalone expansion called The Last of Us: Left Behind. Left Behind was released after the original game and explores what happens to Ellie immediately after Joel is laid out after taking a grievous wound at the University of Eastern Colorado. Just like in the episode, the bulk of the expansion is taken up by a flashback.

The only parts of the episode lifted right from the main game are the scenes with Joel and Ellie at the start and end. In the game, they hide out in a house just like the one they use in the show; in both version, Joel is confined to a mattress in the basement and their horse stays in the garage. Even the sled track outside the house is lifted from the games. That said, the TV dialogue between Joel and Ellie is all new, since in the game Joel remains unconscious for this section.

In The Last of Us game, the story jumps from Joel falling off the horse and passing out to him and Ellie holing up in a vacant house (though there are a few woodland scenes for Ellie in between). The Left Behind expansion fills in the blanks by adding an extra location before they arrive at the house. In the expansion, Ellie and Joel first take shelter in a mall, which leads to Ellie having flashbacks about her last night with Riley. This also explains how Ellie acquires more weapons and spends a little more time on the raiders who injured Joel, both of which are relevant to the next chapter of the main game.

Instead, the show just has Ellie search for supplies in the house, likely leaving further conflict with the raiders for next week. Ellie stitching up Joel’s wound is one of the final scenes from the Left Behind expansion, just like it’s the final scene in the episode.