One of the joys of this season of HBO’s The Last of Us is seeing just how much Craig Mazin and Neil Druckmann were able to change things up from the game. It’s certainly supremely faithful, but the changes have been welcome. And while the season one finale is pretty darned true to the game’s final section, the episode’s prologue is a whole big new section which gave Ellie some fascinating backstory. It all but explains how and why she’s immune.
The episode opens with a pregnant woman running through the forest, trying to evade an infected person. It’s not going well, as you might expect. This person is Anna (Ashley Johnson, who of course played Ellie in the game). She makes her way into an abandoned house but the infected pursue her. She fights for her life and eventually stabs the infected in the head, only then realizing she’d given birth in the struggle.
![Joel (Pedro Pascal) and Ellie (Bella Ramsey) overlook the city in the the last leg of their journey in The Last of Us finale.](https://legendary-digital-network-assets.s3.amazonaws.com/wp-content/uploads/2023/03/10105505/pedro-pascal-bella-ramsey-last-of-us-finale.jpg)
Anna cuts the umbilical cord with the same knife she used to kill the infected. She has also received a bite. This does not bode well for the new mother. Some time later, Marlene enters. Marlene and Anna know each other, evidently have been friends for years. Anna begs Marlene to take her newborn daughter, lying that she didn’t use the knife on the infected before the umbilical cord. Eventually, Marlene accepts, and Anna tells her the baby is named Ellie.
So from this we learn a few things. First and foremost, we know why Marlene knew who Ellie was. She was clearly aware of Ellie, but she put two and two together when the girl they discovered in the mall wasn’t a raving fungus monster despite her bites. Second, this all but confirms the very specific set of circumstances that led to Ellie’s immunity. A pregnant woman gives birth the second she’s bit, uses an infected knife to cut the umbilical. It’s unrepeatable.
![Anna (Ashley Johnson) runs for her and her unborn child's life through a forest in The Last of Us finale.](https://legendary-digital-network-assets.s3.amazonaws.com/wp-content/uploads/2023/03/10105727/ashley-johnson-last-of-us.jpg)
Is this addition to the story strictly necessary? Certainly not. Most people were perfectly happy just to accept that Ellie was immune. Who knows why, she just is? The show, on the other hand, has spent a great deal of time, especially early on, pondering this question. Could there be other people like her? This makes it much clearer that Ellie is a unicorn. She isn’t just the first immune person they discovered; it’s possible she’s the only immune person there is or ever will be.
Therefore, it also makes the ending more profound. It shows us that even Ellie’s mother’s friend looks at the girl more as a means to a cure versus a real person. Conversely, we know that Ellie is the only one who even possibly could provide a cure, but Joel views her as a human first. He fought to keep her alive, and she made him more alive as a result. It’s a morally ambiguous ending even without this context, but Joel officially doomed the world so he could have his daughter back. That’s a hell of a tragedy, and damn compelling TV.
Kyle Anderson is the Senior Editor for Nerdist. You can find his film and TV reviews here. Follow him on Instagram and Letterboxd.