Spoilers for The Last of Us season 1 finale below!

HBO's The Last of Us showrunner Craig Mazin recently explained how a change to the hospital scene in the series made it even more effective than the original video game. The season 1 finale saw Joel (Pedro Pascal) and Ellie (Bella Ramsey) successfully arrive in Salt Lake City at the Firefly's hospital. When Marlene (Merle Dandridge) informs Joel that Ellie will have to undergo lethal brain surgery to create a Cordyceps cure to save the world, Joel takes it upon himself to kill everyone in his path to rescue Ellie.

In a virtual The Last of Us press conference attended by Screen Rant, Mazin discussed a change to the hospital sequence that made it more effective. The showrunner and writer explained they used series and game composer Gustavo Santaolalla's "All Gone (No Escape)" track over Joel's attack against the Fireflies in the hospital. Mazin explained the "mournful" musical piece enhances the dramatic moment allowing the audience to feel "heartbroken" by Joel's actions. Read what Mazin said below:

"There was one option that we had that we employed, I think, to great effect during Joel’s attack sequence in the hospital. And that was to take a very different piece of music that was meant for what happens right after in the game — which is his picking Ellie up and walking out with her — and taking that and putting that under that sequence. In the game, that sequence is largely gameplay. But here, it is this beautiful, sad, mournful cello-based piece. It allowed us to feel almost heartbroken by what Joel was doing and what he was breaking inside of himself and how he was betraying something that he probably knows Ellie wouldn’t want him to do. You’re both rooting for him and you’re also so sad for him. That’s the brilliance of Gustavo is that sometimes just taking a piece from over here and putting it under this makes magic."

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How The Last of Us Finale Changed The Hospital Scene From the Game (And How It Was The Same)

Joel Embraces Ellie in The Last of Us season 1 episode 9 finale

One major difference between the hospital scene in the show and in the game centers on how Joel and Ellie arrived at the facility. The season 1 finale had Joel and Ellie attacked by a Firefly patrol, leaving Joel unconscious and Ellie relatively unharmed. However, the game had Joel and Ellie navigate past a dozen infected in a highway tunnel resulting in Ellie nearly drowning. The Firefly patrol discovers the two as Joel attempts to perform CPR on Ellie. This is a significant change as Ellie does not have the opportunity to talk to Marlene before the operation and instead remains unconscious until the surgery.

The Last of Us season finale also alters what happens immediately after Joel locates Ellie in the hospital. In the series, Joel scoops up Ellie and quickly makes his way to a nearby elevator without any trouble. However, the game has the player retrieve Ellie with a platoon of Firefly soldiers on his tail. After grabbing Ellie, Santaolalla's "All Gone (No Escape)" plays as Joel runs across the hospital floor, desperately searching for an exit.

The game sequence is intended to mirror the beginning of The Last of Us, where Joel had to carry his daughter Sarah away from murderous infected. Similarly, Joel found his escape blocked by a lone gunman. Instead of pleading with Marlene as he did with a soldier in the field, Joel took Ellie's fate into his hands and killed the Firefly leader. With The Last of Us season 2 over a year away, there are questions about whether Ellie will ever discover the truth regarding Joel's brutal actions in the hospital.

More: 6 Ways The Last Of Us Season 1 Finale Sets Up Season 2