As HBO’s The Last of Us approaches the end of its first season, it’s clear this is a different kind of post-apocalyptic show. Other TV series that depict the brutal breakdown of order, like The Walking Dead or Game of Thrones, revolve around how far you can push an ends-justify-the-means worldview in order to protect the people you love. The Last of Us is interested in a different question. What does it mean to love someone when you know you can’t keep them safe? The show is haunting because it understands how it feels to have someone count on you when everything else falls away.

Maybe it’s because The Last of Us is set 20 years after the world ended—when most of the population became infected with a fungus that turns them into flesh-eating, bizarrely beautiful zombies—but is doesn’t spend much time wrestling with who is good in this world, because the answer is simple: No one is. At least no adults, not really. But there is a line the show won’t cross, a refusal to justify certain actions, even if they’re taken in the name of survival. You can’t protect the people you care about at all costs. That’s what makes it so scary to love.

One of the great strengths of The Last of Us is its ability to sketch lives and relationships in a relatively small amount of screen time. As we follow Joel (Pedro Pascal) and the teenage Ellie (Bella Ramsey), who is immune to the Cordyceps fungus and could be the key to a vaccine, we see the different ways people have coped with the impossible questions this world poses. In “Left Behind,” a heartbreaking mini coming-of-age story, Ellie and her best friend Riley explore an old mall and realize they have feelings for each other just before an infected person attacks and bites them both. Bill and Frank, the focus of the capsule episode “Long, Long Time,” are a classic foxhole couple like TWD’s Maggie and Glen—they would never have gotten together in the before times but turn out to be the loves of each other’s lives. And in the few scenes where we see Joel with his teenage daughter Sarah before the outbreak, the simple act of their watching a DVD together reveals how much they love each other.

In most dystopian shows, depicting loving relationships is a way of raising the stakes—showing how much characters have to lose and why they are driven to extremes. But in The Last of Us, the relationships the show brings to life so briefly and beautifully are in the past: Sarah is dead, Riley is dead. Bill and Frank probably get the closest thing to a happy ending we’ve seen so far, slipping away peacefully in a suicide pact after Frank develops a terminal disease. What is so beautiful about their love story is that, after almost 20 years spent keeping him alive, Bill accepts Frank’s desire to die on his own terms. His relentless quest to keep Frank alive has a limit.

We know Joel feels that the only thing that matters is keeping the people you love safe, because he’s haunted by his failure to keep Sarah alive, but The Last of Us has another argument to make. There are worse things than dying, or loss. Yes, it’s terrifying to have someone count on you: As Bill, who was a solitary, misanthropic survivalist until he met Frank, tells him, “I was never afraid of anything until I met you.” But it’s worse to have no one count on you at all.

Joel fights this idea as long as he can, but we see him slowly accept the fact that he cares for Ellie, his willingness to let the old fear in again. In the hands of lesser actors, the bond between Joel and Ellie might feel trite. But Pascal gives a performance so restrained and disciplined you feel every moment of closeness—his simple act of standing watch over Ellie when he’s supposed to be sleeping, or deadpanning the answer to one of Ellie’s ridiculous puns, or putting her seatbelt on the first time she’s in a car. “You shouldn’t have had to do that,” he says to her when she shoots and wounds an attacker to save him. Despite her countless requests, he’s refused to give Ellie a gun, and in that moment, you realize it’s not because he didn’t trust her, but because he wanted to spare her the anguish of taking a life. In the apocalypse, that’s what protecting childhood looks like. As Ellie, Ramsey is uncanny at capturing the vulnerability and resilience that, even under the pressure of an apocalyptic world, are still recognizably teenaged.

But we don’t really understand how much it costs for Joel to bring back the muscle memory of fatherhood until he breaks down to his brother Tommy, telling him that he’s sure he’s going to get Ellie killed. “I have dreams every night. I can’t remember them, but I just know when I wake up, I’ve lost something,” he says. “I’m failing in my sleep. It’s all I do, it’s all I’ve ever done.”

What are the limits when you are responsible for another life? It’s a question that comes into intense focus in the eighth episode, “When We Are in Need,” which deals with a post-apocalyptic fixture we haven’t encountered yet in The Last of Us: the religious cult. In a twist, it turns out that the man who Joel killed in self-defense at an abandoned Firefly medical facility was a member of a group led by a charismatic preacher, David. The man had a family, and to the group, Joel is the villain. We all know that Joel has a violent past, but in this accusation, he is innocent.

While David preaches a standard-issue message about God’s forgiveness and having a plan, he’s secretly feeding his flock human flesh and probably preying on its younger members. He’s also the only character who tries to dress up his choices as moral, because, as he tells Ellie, people have put their lives in his hands. It’s not a line that Joel would ever utter. Joel may be ruthless—and we see just how ruthless in this episode—but he’s not self-righteous.

When the men come for Joel, who is badly wounded, it’s Ellie who leads them away from him, and it’s this act of selflessness—her refusal to abandon him—that basically brings Joel back online. We see both the father he was before the outbreak and the brutally violent Joel we’ve only heard hints of. When he tortures two men to find out where they’ve taken Ellie, it’s hard to watch. But we also know what’s finally driving him.

There are no “good” people here, but in the universe of the show, David’s bad faith crosses a line. He dresses up his murdering and cannibalism as leadership, chasing ends-justify-the-means to its most gruesome end. It’s a different transgression than, say, Henry’s, the FEDRA collaborator who betrays the leader of the Kansas City resistance, a man he loves and admires, in order to get lifesaving drugs for his younger brother, Sam. “I’m not a good person,” he tells Joel matter-of-factly, and he can live with that, because Sam is counting on him. But no one pretends Henry had a right to do what he did. “Kids die, Henry,” Kathleen, the sister of the man he betrayed, tells him. “They die all the time.” And she’s right. That makes it all the more devastating when Henry kills his brother after Sam becomes infected, and then kills himself. Henry’s protectiveness does not extend to letting Sam rip Ellie apart, and he realizes his brutal sacrifices were for nothing.

Of course, the thorniest piece in this murky morality tale will be Ellie. She is immune–does that make hers more important than other lives? The show hasn’t answered that question yet. But what it has answered, definitively, is that there is a difference between men like David and Joel. Joel may push limits in protecting her, but it is David who tries to manipulate her and then attacks her, pinning her down and saying “Don’t be afraid, there’s no fear in love,” right before she ends him with a cleaver. If there is one truth to this story, it’s that fear is always part of love. The real divide in The Last of Us is not between good and evil, but between whether you are still capable of that love or not.

When Joel finds Ellie, holding her to him and calling her “baby girl” like he did Sarah, it’s clear he’s decided to live with his terror, to lean into the fear that comes with loving another human being. He tells Ellie it’s OK, and we know it isn’t. But we also know the alternative is worse.