If you’re like me, you probably spent a good chunk of The Last of Us Episode 3, "Long, Long Time," with a massive lump in your throat. It’s arguably one of the best hours of television ever made, but it leaves us with a nagging, heavy question. After surviving the literal end of the world for twenty years, what does Frank have in The Last of Us that ultimately leads to his decision to end his life?
It wasn’t the Cordyceps. It wasn’t a raider’s bullet. It was something far more "normal" and, in many ways, more terrifying because it was a ghost from the old world that followed him into the new one.
The Short Answer: A Neuromuscular Disorder
Let’s cut to the chase. Frank is suffering from a degenerative neuromuscular disorder. If you’re looking for a specific name like "Parkinson’s" or "Cancer," the show actually stays a bit vague on purpose. Why? Because in a post-apocalyptic world without MRIs, neurologists, or blood labs, there is no way for Bill or Frank to get a formal diagnosis.
However, showrunner Craig Mazin hasn't left us totally in the dark. In the official The Last of Us podcast, he mentioned they specifically had diseases like ALS (Amyotrophic Lateral Sclerosis) or MS (Multiple Sclerosis) in mind.
📖 Related: Isaiah Washington Movies and Shows: Why the Star Still Matters
Spotting the Symptoms: Why He Couldn’t Just "Get Better"
By the time the timeline jumps to 2023 in the show, we see a drastically different Frank than the one who fell into Bill’s pit years earlier. The progression is heartbreakingly realistic.
- Loss of Motor Control: Frank is first seen in a wheelchair. Later, we see him struggling to paint—something he used to do beautifully. His hands just won’t do what his brain tells them to.
- Chronic Pain: He mentions that "everything hurts," a common symptom of the nerves misfiring or the body physically breaking down from lack of mobility.
- Incurable Status: Frank tells Bill that there was no cure for what he has "even before the world fell apart." This is a key line. It rules out things like basic infections or treatable cancers and points directly toward those heavy-hitter neurological conditions.
Why the Show Changed This from the Game
If you played the original 2013 game, you might be scratching your head. In the game, Frank doesn't have a slow-burning illness. Honestly, his story is way bleaker.
In the Naughty Dog version, Frank grows to resent Bill’s overprotective, stifling nature. He actually tries to leave Lincoln. While trying to get a car battery, he gets bitten by the Infected. Rather than turn, he hangs himself in a random house, leaving a scathing suicide note for Bill that basically says, "I hated your guts."
👉 See also: Temuera Morrison as Boba Fett: Why Fans Are Still Divided Over the Daimyo of Tatooine
The HBO series took a 180-degree turn. By giving Frank a terminal, "natural" illness, the creators shifted the focus from a failed relationship to a story about enduring love. It showed that even when the world is ending, the biggest challenge isn't always a mushroom-headed monster—it's just the reality of getting older and losing the people you love.
The Medical Reality: ALS vs. MS
While the show stays vague, fans with medical backgrounds have spent a lot of time debating which one fits better.
ALS (Lou Gehrig’s Disease) is often the top guess. It’s a progressive disease that kills off motor neurons. It’s aggressive, often taking someone from "fine" to "unable to breathe" in just a few years. Frank’s steady decline over the final years of his life fits this pattern quite well.
✨ Don't miss: Why Tinker Tailor Soldier Spy Actors Still Define the Modern Spy Thriller
Multiple Sclerosis (MS) is also a candidate, though it often involves "flare-ups" and remissions. In a world without modern steroids or immunosuppressants, MS would likely progress much faster and more painfully, which aligns with Frank’s situation.
How Frank’s Choice Changes Joel’s Journey
Everything in The Last of Us is a mirror for Joel. Frank’s illness and his eventual choice to die on his own terms serve as a massive "What If" for the main characters.
Bill’s letter to Joel says it all: "I used to hate the world... but I was wrong because there was one person worth saving." By seeing what Frank had, and how Bill cared for him until the very end, Joel realizes that surviving isn't just about not getting bitten. It’s about having something to live for.
Actionable Takeaways for Fans
If Frank's story touched you and you want to understand the real-world context of what he went through, here are a few things you can do:
- Learn about Neurodegenerative Health: If you want to see the reality of what the creators were mimicking, the ALS Association and the National MS Society provide incredible resources on how these conditions actually affect families today.
- Watch the Official Podcast: To hear Craig Mazin and Neil Druckmann explain the "why" behind Frank's illness, check out Episode 3 of the HBO The Last of Us Podcast. It gives a lot of nuance to the "no diagnosis" decision.
- Re-read Bill's Letter: If you missed the details, go back and watch the end of the episode. The letter Bill leaves for Joel isn't just a plot device; it's the mission statement for the entire series.
Frank didn't have a "zombie" problem. He had a human problem. And in a show about the end of humanity, his struggle with a "normal" disease made him one of the most relatable characters on screen.