This post contains spoilers for both "The Last of Us" TV show and "The Last of Us Part II" video game.

"The Last of Us" is a fantastic adaptation of a video game. It recreates some scenes very faithfully — to the point where it sometimes feels like watching a walkthrough video — but also makes significant changes to the source material in other places. Most of these add context to the story and flesh out the world of the show, like giving Bill and Frank a different fate.

There are also changes brought about thanks to the power of hindsight. Knowing where the story goes, "The Last of Us" HBO show has an opportunity to plant seeds to where each character ends up in interesting ways so that they don't feel like they come out of nowhere. We've already seen this with a small tease of a fictional movie first mentioned in the "The Last of Us Part II" video game.

This week's episode takes a bit of a break from the main story of the games, and fully adapts the DLC "The Last of Us: Left Behind." That expansion pack serves to flesh out Ellie's backstory, showing how she got infected and how she lost someone close to her, adding context to her relationship with Joel. The episode's version, however, also serves an additional function: hinting at the very dark turn Ellie takes in the second game, and all the violence and death that brings.

If You Seek Revenge

"The Last of Us Part II" starts with Joel being murdered by a group of former Fireflies seeking revenge on him for killing their own at the end of the first game. This prompts Ellie to go on a violent, hellbent path of revenge and death, traveling to Seattle and killing everyone she comes across. Throughout the game, Ellie becomes a cold and scary killer, one that tortures for information, and even kills a pregnant woman. We see her victims' eyes bulge as she cuts their throats, and we hear their screams as she blows them to bits.

Very quickly, as the situation escalates out of control, Ellie's friends and companions start pleading with her to give up her senseless quest for revenge and go home. Even Joel's brother, Tommy, decides enough is enough, but Ellie keeps going. She goes to hell and back for revenge, losing every person she loves, and even a couple of fingers in the process.

For some players, this turn came out of nowhere: an abrupt change in the characterization of a beloved character. What the latest episode of "The Last of Us" does is show that Ellie's inability to know when to stop fighting started years before her rampant in Seattle.

In "The Last of Us" episode 7, we meet Ellie before she was a survivor traveling through the post-apocalyptic landscape of America. Here, she is a regular girl who has friends and goes to school, but also a girl who constantly gets into fights.

You Should Dig Two Graves

We see Ellie fighting a classmate over comments about Ellie's roommate and best friend, Riley — something so common that both Riley and even the school principal and military leader mention it. At one point, Riley tells Ellie she can't fight everything and everyone, "you can pick and choose what's important," teasing the horrors to come.

Riley herself has just returned after disappearing for three weeks. Turns out, in that time, Riley joined the Fireflies, a group of freedom fighters who are constantly fighting and killing FEDRA agents. In fact, Ellie says she has Firefly-killing drills at school the next day. While this is a big deal for Riley, who finally found a group she belongs to, a family, and a purpose, Ellie refuses to see them as anything other than the anarchists and terrorists that FEDRA says they are. She constantly teases Riley about her decision to join the group, whether she is brainwashed, and whether she likes bombing innocents. No matter how hard Riley tries to explain what the Fireflies do, Ellie refuses to listen.

This is a big change from the source material, where Ellie doesn't really care about Riley joining the Fireflies. In the video game, Ellie is angrier at Riley leaving than her joining the group, and even asks if she can join just to be together with Riley.

Making Ellie fundamentally oppose the Fireflies in their fight against FEDRA — who we now know are the absolute worst — and refuse to see things any other way than her own brings her closer to the Ellie we meet in the second game. It's a small change for this particular episode, but one that shows HBO's adaptation is already thinking of the bigger picture.

Read this next: 12 Things We'd Like To See In HBO's The Last Of Us

The post The Last of Us Episode 7 Sets the Stage for the Second Video Game appeared first on /Film.