The penultimate episode of “Lanterns” Season 1 introduces remarkable oddities like dark matter portals, dead alien worlds, and a dangerous ride across the river Styx, but it’s what becomes of Hal and John’s late-maturing bond that really lingers.

SPOILER ALERT! This post contains details from the penultimate episode of HBO‘s Lanterns.

HBO’s Lanterns gave audiences, and John Stewart (Aaron Pierre), a much deeper understanding of Hal Jordan (Kyle Chandler) in the penultimate episode of the DC series on Sunday night.

The episode opens with a flashback to 1975, when Hal gets in trouble with his baseball coach for refusing to hand over the ball to his teammates. Sound familiar? Back in present day, John has managed to exhume Hal’s body and retrieve the decommissioned power ring, awakening the Halogram to get his help opening the lockbox in the storage unit. It works, and they soon discover that the lockbox contains a dark matter manhole to another planet.

For all the strife that Hal has caused John up to this point, even in his death the partners in intergalactic crime find their way back to one another again.

“We used to describe each other as these characters, like two dogs who lived in the same household, who, at home, they would maybe fight and tear each other apart, but when they were going for maybe a walk, and another dog entered the equation, bam, they were a unit, and there was nothing you could do to to to disrupt or destroy that unit,” Pierre said. “They become dangerous when they’re together. The dynamic is unbreakable, and as soon as they’re on their own, they’re tearing each other down and apart.”

On the other side of the dark matter manhole, the pair find themselves on a deserted planet which seems to have already been utterly destroyed. John soon deduces that this is Anton’s (Paul Ben-Victor) planet, the one that had been systematically that wiped out by the Manhunter.

The Halogram’s decade of missing memories and context create even more frustration for John, who’d gone back to Rushville in the first place because his mother had told him that Hal was ready to apologize for everything he’d done. He was dead by the time John arrived, and this version of him wouldn’t even know what to apologize for. Not to mention, they’ve got more pressing issues. When John becomes affected by the same gas that made Anton’s people kill themselves, the Halogram is the only thing that saves him.

“I think his understanding of who Hal is certainly evolves over the course of the series,” Pierre tells Deadline. “It’s almost like throughout these episodes, John is putting together a puzzle, but the puzzle is 1000 pieces, and sometimes elements of that puzzle form before others, and he thinks he has an understanding of exactly who Hal is, and then he formulates another part of the puzzle, and that conflicts with what he thought he understood, and it’s an ongoing thing.”

The piece of the puzzle that clicks into place this episode harkens back to Hal’s childhood. Not only does that 1975 flashback illustrate Hal’s complicated relationship with his father, it also reveals a history of mental health struggles when Hal reveals that his father killed himself. Since he was a test pilot, no one batted an eye. Among the things he left behind was a note that told Hal he’d be better off without him — and a lifetime of trauma for his son. It was a cycle that had repeated itself for generations in Hal’s family: The Jordan boys’ legacy.

“I’m not fearless because I’m brave. I’m fearless because I’m broken,” the Halogram tells John.

The “heartfelt moment” as Chandler calls it, reframes Hal almost entirely. It follows another moment earlier in the episode, when Kerry (Kelly Macdonald) tells John that Hal once described his trainee like someone’s favorite football team: Impossible to root against but exceedingly maddening to remain loyal to.

“That’s not information that someone just throws in there. That’s a detailed storyline that is also meant to manipulate an audience’s emotions and bring them that much closer into the whole story,” Chandler said. “That’s another great thing about this whole show is that there are those fence posts along the way, and they’re pretty detailed. You don’t miss them in scripts, and you can build around those things as an actor too.”

The end of the episode finds Hal and John facing yet another foe: Sinestro. Turns out, this planet is where he’s been hiding all along.

As for how John’s revelations about Hal might impact the finale, Pierre remains coy about exactly what’s in store, telling us: “I won’t reveal the end, but once we get very near to the end, at least, he has this immense respect and appreciation for Hal, and if if nothing else, I think even Hal knows that he could trust John with his life, and John knows that he could trust Hal with his.”

“You don’t always need to love each other for that to be a truth, and I think that’s something that this series explores. But interestingly enough, speaking on that love element, I think that there is a very there’s a very sincere respect and and a mutual brotherly love there between the two of them,” Pierre continued. “I think a truth that John understood at a certain point in the series [is that] he’s never gonna fully know Hal, but what he can do is understand who Hal is fundamentally at his core, at least. He may never understand all of the nuances of who this individual is, but he can discover who this man is at his core. And once that curiosity was satisfied, I think he was very at peace with everything that the two of them had been through — the highs, the lows, the inbetweens, the moments that felt like purgatory. I think he just he just finds peace with it, because he knows who this individual is at his core, no matter what decoration or nuances surround it.”

Lanterns ends next Sunday at 9 p.m. ET/PT on HBO.