As an adaptation, HBO’s The Last of Us has been a fairly faithful recreation of Naughty Dog’s original game. However, during yesterday’s season one finale, “Look For The Light,” HBO’s series explored a character the game had only talked about in passing mentions. In doing so, the show reveals a long unanswered question from the source material: why is Ellie immune to the cordyceps fungus that has destroyed the rest of the world?
The episode opens with a flashback of Ellie’s mother Anna, portrayed by Ashley Johnson, who plays Ellie in the games. She’s on the run from an infected while also going into labor. She holes up in an old farmhouse with only a switchblade to protect herself. Eventually, the infected finds her and the two have a scrap on the floor in which Anna is bitten, but she also gives birth to Ellie in the process. Anna cuts the umbilical cord, but this occurs after she was bitten and starts to succumb to the infection herself. When Marlene, a lifelong friend and leader of the Fireflies, arrives, Anna lies and says that she cut the cord before she was bitten, and asks Marlene to find a home for Ellie, and give her the switchblade to remember her by.
Fast forward to 14 years later, and Ellie is in the care of the Fireflies’ doctors, and Marlene explains to Pedro Pascal’s Joel why they believe she is immune.
“Our doctor, he thinks that the cordyceps in Ellie has grown with her since birth. It produces a kind of chemical messenger. It makes normal cordyceps think that she’s cordyceps. It’s why she’s immune. He’s gonna remove it from her, multiply the cells in a lab, produce those chemical messengers, and then we can give it to everyone.”
Marlene goes on to say this could be a cure for the infection, but this process would require Ellie’s death, as cordyceps grows all over the brain. Because of Joel’s violent intervention, this never comes to be, but it is the most context we’ve gotten for Ellie’s immunity in the decade since the original game. This scene in the game simply chalks Ellie’s resistance to the infection that has ended the lives of so many others as a kind of mutation, but it never got too into the science.
Despite this, series director Neil Druckmann told The Verge this isn’t necessarily meant to be a conclusive line drawn between the circumstances of her birth and why she’s immune, though we (and Marlene) can speculate. Instead, he says revisiting Anna’s story was meant to build upon her relationship with Marlene, which was, again, only ever explored in passing mentions during the games and American Dreams comics.
“Knowing how close she was with Anna, and that Anna’s dying wish was like, ‘take care of my kid,’ I think gives more weight and maybe more tragedy to Marlene and the sacrifice she’s trying to make for the betterment of mankind,” Druckmann told The Verge.
Notably, the circumstances surrounding Ellie’s birth seem a little bit different from the games. In the first game, Anna was able to write a letter to Ellie, which is visible in her inventory during the segments where you play as her. It’s clear she died not long after giving birth to her, but it’s unclear if this fight with an infected was part of it.
The Anna scene is one of the few deviating moments for the finale, which plays out pretty close to the story beats of the game. Though the framing does feel a bit different after conversations between Joel and Ellie do a lot of work to contextualize Joel’s actions in the final moments.