The Last Of Us Finale Reveals Ellie's Immunity Story And Proves Why Joel Was Never Meant To Be The Hero

Major spoilers below for The Last of Us, so be warned if you haven’t yet watched the HBO series’ finale.

HBO’s The Last of Us co-developers Craig Mazin and Neil Druckmann basically promised from the start that the first season would lay out the storyline from Naughty Dog’s first video game in full without superfluous expansions, and many gamers wondered how the TV show would handle adapting the ethical apocalypse that closes out the source material. Put simply, the finale was almost surprisingly faithful to the complicated way Joel and Ellie’s story first wrapped up, with Pedro Pascal’s emotionally corrupted character forever losing his co-hold on Hero status with Bella Ramsey’s matured teen. (Though he certainly won all the remaining Surrogate Dad merit badges.)

What’s more, the Last of Us’ ninth installment also delivered guest star Ashley Johnson to help explain Ellie’s origin story via the most tragic easter egg ever. 

Anna in The Last of Us finale

(Image credit: HBO)

Ellie's Immunity Story Explained, More Or Less

Following the horror drama’s pattern of flashback cold opens, “Look for the Light” kicked off with The Last of Us games’ Ellie voice actress Ashley Johnson taking on the live-action role of the immune teen’s mother. This marks a big change from the games, as Anna hadn’t pulled focus within the franchise before now, and was only mentioned in conversations between Marlene and Ellie; her words were also imparted through a letter she wrote for her daughter to eventually read years later, which Marlene gifted Ellie along with her mom’s switchblade.

Within the HBO series, Anna went into labor while trying to escape a Runner, and though she managed to put the creature down, she was bitten in the process. After discovering that she’d given birth during the struggle, Anna cut the umbilical cord and had to basically starve li’l Ellie while waiting for Marlene, who was then given the responsibility of caring for her BFF’s newborn on top of killing said BFF. The fact that Anna might have been saved if not for Marlene being delayed is kind of a pisser, but so it goes. 

  • Related note: Johnson’s character was as forceful as a Cordyceps-stricken person could be about Marlene telling others that Ellie’s cord was cut before the bite, but I’m not 100% sure why it happened. I get it from her viewpoint as a mother, but I feel like because Marlene knew that was bullshit, she would already be keeping a safely-distanced eye on Ellie during that first day or two just to be sure the fungi hadn’t instantly been transferred through the mother-daughter bloodstream. 

Later in the episode, when Joel awoke to armed Firefly soldiers in the Salt Lake City hospital, Marlene laid out what was essentially a working theory for Ellie’s immunity. And it’ll have to be the best answer to that question, since nobody had the chance to prove it correct. In Marlene’s words:

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 to produce those chemical messengers, and then we can give it to everyone. He thinks it could be a cure, Joel. A cure.

The reason why no one will put that hypotheses to the test, of course, is because the bulk of the people who were part of the research process were killed in cold-blooded desperation. Which leads us to…

Joel concerned in The Last of Us finale

(Image credit: HBO)

Why TV Joel Isn't The Hero That Video Game Joel Was

HBO’s The Last of Us does what very few video game adaptations can do, in that it can completely change a player’s ideas about who these characters are. The biggest example of that would arguably be the third episode’s poignant exploration of Nick Offerman’s Bill bonding lovingly with Murray Bartlett’s Frank, but I’d say the finale provided the second most meaningful gut-check in that respect by way of Joel choosing to save Ellie over the possibility of saving the rest of humanity, and then lying to her about it afterward. Especially after making such a big move for her trust by telling her about his suicide attempt.

When players guide Joel into the game’s hospital massacre, the inevitability helps to ignore all of the ethical bile oozing from one’s conscience. Ellie is as much a makeshift daughter for gamers as Bella Ramsey’s loveable badass is for Pedro Pascal’s morally tapped-out survivor. So it’s shocking to experience and be put in that position, but a battle that had to be fought, with the outside assumption that maybe Joel would find more scientists somewhere who could figure out how to utilize’s Ellie’s immunity without having to kill her.

On the TV show, however, the absence of Viewers-As-Joel perspective totally skewed things for me, and I came away from the finale feeling far more like Joel is a selfish kinda-monsters who two-handedly fucked up any chance for humanity’s future by duping himself into thinking he and Ellie could live a normal father-daughter existence back at Tommy’s. And I guess in some ways, this does give him a few Hero points, since it’s seeing Ellie’s childlike awe and glee over feeding a giraffe that kept him in the mindset that her life was the one worth saving. And it was, since Ellie is the real hero here, but that doesn’t excuse everything!

In the hospital, Joel displayed the same callous and empathy-free behavior that he did coming out of his infectious state during Episode 8’s chaos, when he brutally tortured and killed the two vengeance-minded members of David’s flock. He left a gobsmacking body count in his wake while trying to track Ellie down, in one of the show’s relatively few hyper-violent scenes that were pulled straight from the video game, and seemed to only leave two people left standing by the time he and Ellie were on the road again: the two nurses who were assisting in Ellie’s brain-removing surgery were only told to turn around while Joel took her away, after he’s already put a bullet in the surgeon’s brain. (These details may or may not play exceedingly important roles in Season 2, depending on where the co-creators take things.)

Not even Marlene was left standing, since she’d crossed the line by allowing Ellie to be put into the surgery in the first place. He probably thought all the worse of her, too, after she explicitly talked about promising Anna to keep her daughter safe. Because he probably could have just left her bleeding in that parking garage, since he didn’t leave many people around to help her out. But the possibility that it could happen was enough to take her out of the equation.

For all the bloody horror that happened in the episode’s first 40-or-so minutes, Joel barreled through the point of no return by first lying to Ellie about why they left the hospital. Saying she wasn’t special in being immune would already be a weird blow to the kid’s mental space, but he stepped up onto that and claimed that they were giving up on trying to find a cure. Her bullshit detector went off immediately, but she waited until they were almost back into Wyoming civilization to truly test him by asking him to swear that he’d been telling the truth about the hospital. He did it without hesitating or thinking twice, and the look on Ellie’s face in the end was all the evidence needed to know that their bond has possibly forever soured, just when viewers were digging their pun-geared laughter again. 

It's certainly possible that the span between Season 1 and Season 2 could feature some moment where Joel just casually drops the info-bomb that he'd lied about it all, and crushed all chances for a cure or vaccine. But I wouldn't count on it after seeing the look of perma-shock on Joel's face throughout most of the finale. Even though he thinks he's made it past his former grief, it's just another layer for him to dig through while Ellie continues her reign as The Last of Us's true Hero. 

Now to start playing The Last of Us Part II again while waiting for HBO's second season to start filming. It's going to be weird hearing Ashley Johnson as Ellie again, but like, the best kind of weird. 

Nick Venable
Assistant Managing Editor

Nick is a Cajun Country native and an Assistant Managing Editor with a focus on TV and features. His humble origin story with CinemaBlend began all the way back in the pre-streaming era, circa 2009, as a freelancing DVD reviewer and TV recapper.  Nick leapfrogged over to the small screen to cover more and more television news and interviews, eventually taking over the section for the current era and covering topics like Yellowstone, The Walking Dead and horror. Born in Louisiana and currently living in Texas — Who Dat Nation over America’s Team all day, all night — Nick spent several years in the hospitality industry, and also worked as a 911 operator. If you ever happened to hear his music or read his comics/short stories, you have his sympathy.