Why Is Ellie So Important On ‘The Last Of Us’?

The first episode of HBO’s The Last of Us introduced us to a new kind of zombie apocalypse and the people trying their best to survive in it. Like its video game counterpart, the Craig Mazin and Neil Druckmann-created series focuses more on its characters than its creatures – though those fungi-infected bodies are terrifying in their own right. One such character is Ellie, a teenager living in the Boston Quarantine Zone (or QZ) and played by Game of Thrones standout Bella Ramsey.

Ellie’s important enough that the Fireflies — the rebel group opposing the military dictatorship currently running things in the QZ – are willing to sacrifice their whole militia to smuggle her to safety. But who is she and why does she matter so much?

Here’s everything we know about Ramsey’s character on The Last of Us.

Who Is Ellie Williams?

The show only introduces Ramsey’s smart-mouthed teenager as Ellie, but thanks to the game, we know her last name is Williams. She’s an orphan, having grown up in the QZ which means she doesn’t know much about the world before the Cordyceps outbreak. Like in the game, Ellie has spent her life being trained to be a soldier for FEDRA – the government organization responsible for keeping QZ citizens in line. Apparently, that’s the fate of most orphans in this post-apocalyptic world. But we know that Ellie has some kind of connection with the Fireflies leader, Marlene after the group holds her hostage on Marlene’s orders.

What is Ellie’s Relationship To The Fireflies?

In episode one’s “When You’re Lost In the Darkness,” Marlene tells Ellie she not only knew her birth mother but promised to keep her safe. That’s why she dropped her on FEDRA’s doorstep as a baby and it’s why she made sure her soldiers didn’t shoot her when they discovered she’d been “bitten” by an Infected. We don’t know much about Ellie’s mom at the moment, but it’s likely she knew Marlene and her plan of rebellion since the early days of the pandemic.

Marlene also mentions the name “Riley” to Ellie, implying they share another tie in the character that is played by Euphoria’s Storm Reid – though, she hasn’t made an appearance as of yet. It sounds like Riley was a close friend of Ellie’s and possibly a member of the Fireflies, which is another reason Marlene had Ellie on her radar.

Why Is Ellie Important?

Members of the Fireflies begin to ask questions when Marlene decides to abandon the Boston QZ for good to smuggle Ellie out of the city. She’s not only risking the lives of all of the soldiers under her command for a teenager, but she’s also throwing away 20 years of hard work resisting FEDRA’s rule. Why? Because Ellie might hold the answer to creating a cure for the Cordyceps Brain Infection, or CBI outbreak.

Though we don’t witness it, we soon learn that Ellie has been infected thanks to a mostly healed bite shown on her arm. When we meet her, she’s being tested to make sure she isn’t showing any of the normal symptoms associated with the Infected. Those signs should’ve presented in a matter of days, but it sounds like Ellie has had the bite for weeks at this point, which means she’s immune to the fungus. According to Marlene, the Fireflies have an outpost out West where doctors might be able to reverse engineer a cure – or at least a preventative measure like a vaccine – using Ellie’s immunity. Naturally, being the potential savior of mankind makes Ellie a valuable asset, which is why Marlene sacrifices much of her group, eventually turning to Joel (Pedro Pascal) and Tess (Anna Torv) to get Ellie out of the city.

Whether the trio will make it to their destination alive, and whether Ellie’s immunity can actually be replicated is still anyone’s guess.

The Last of Us airs Sundays at 9 p.m. ET on HBO.