"I used the stones to destroy the stones."

Thor's breath hitches in his throat.

The Infinity Stones are gone. The world's last hope – the universe's last hope – is gone.

Thanos snapped away half of the entire universe, and they're just... gone.

Forever.

Thanos keeps talking. Thor doesn't listen.

The others start talking. Thor doesn't listen.

His vision begins to blur, like the world is fading away around him, until all he can see is Thanos. That smug little bitch.

Thor has lost everything. He lost his brother when a bout of insanity sent him tumbling from the Bifrost. He lost his mother when the Dark Elves attacked the Asgardian Palace, and he lost his father only a few years later when the grief drove him mad. Hela killed the Warriors Three and then Surtur destroyed what remained of Asgard, but he'd thought they'd be safe after that. Then the Snap stole the only friends he had left.

He'd just thought that if they could get the Infinity Stones, everything would be okay again. He couldn't bring back his family and he couldn't bring back his home, but he could bring back the Asgardians he'd evacuated from his homeland. He could bring back Heimdall. He could bring back Sif.

He could bring back the universe.

But the Infinity Stones are gone, and with them, any hope of salvation.

Thanos took everything he had left. It's time for Thor to repay the favor.

He doesn't know what's happening around him, and he doesn't care. Whatever conversation they're having, it doesn't matter. If the Infinity Stones are gone, then Thanos is nothing to them.

He charges forward and raises his axe above his head, then slices it down–

"No!"

That cry comes too late.

Thanos's head hits the floor, and his body follows only a moment later.

And then another shape appears. Thor doesn't know whose. He doesn't care whose. He doesn't care who it is rushing to Thanos's side. He doesn't have even an ounce of sympathy for whoever would mourn the man who destroyed half the universe. To see someone sprawl out over him is nothing short of disgusting, and if it had been any other moment, Thor would have killed them, too.

"What?" Bruce's voice is a blur in the background.

"Who is that?" Natasha's voice is no clearer.

"What did you do?" Rocket asks cautiously.

"I went for the head."

Thanos never should have told him his weakness. Thor may not have done it if he hadn't been certain it would kill him. But he was so cocky, so smug, so unbearably arrogant about the atrocities he's committed, that when Thor saw that chance, he didn't have a choice. He had to take it.

As the pounding of Thor's heart begins to slow, the rest of the world comes back into focus. He can hear the others discussing plans for what happens next. One common question is what happens to Thanos's only mourner.

Thor watches him with disdain. The man is sobbing into Thanos's lifeless corpse, his cries echoing throughout the hut they reside in. His long, dark hair is splayed out against the Titan's body, tumbling down to the ground. He must live here, too, in this near-empty world, if his muted tan clothing is any indication. It matches the ridiculous garments Thanos wore, perhaps fitting for the life of a farmer, but that's certainly not what they are.

There have been a few suggestions of what to do with him. Killing him is perhaps the most popular idea, though it's suggested once or twice that they take him with them and let him face punishment elsewhere.

Thor interrupts with a booming, "Leave him. Let him rot in this prison of his own making." Any friend of Thanos is a foe of theirs, and what worse punishment is there than total isolation, alone with the corpse of his former companion?

But then he lifts his head, slowly, carefully, until he meets Thor's gaze. There's a murderous glint in his eye, strong enough that even the tears he wears on his cheeks make him look like no less of a threat.

But he's not a threat.

He's...

"Loki?"

It's not possible.

Loki is dead. Thor saw him fling himself from the Bifrost. He couldn't have survived that. It's impossible. And yet, this man in front of him, it's unmistakably him.

He's changed a lot in the years they've been apart. His hair has grown far longer than it's ever been. His skin has grown paler; his eyes darker and sunken in. His arms are littered with scars, nearly hidden in the darkness of the hut, though the scarred gash across his cheek is impossible not to notice.

But it's still his baby brother.

His baby brother doesn't seem to care.

"What have you done?" he growls.

Thor swallows hard. This isn't... this doesn't make sense. When Loki "died," they parted on bad terms, he'll admit, but not like this. Not enough so that Loki should choose a genocidal maniac over his own brother.

"Uh, Thor?" Rhodey says awkwardly. "You know this guy?"

Thor can't take his eyes off his brother – or the shell of him that remains. He should say something. He knows that. He needs to say something. But he can't.

A flash of green covers Loki's hand, and when it fades, a knife is in its wake.

Thor takes a cautious step back. "Loki..."

"What have you done?" His scream pierces the air like a bullet, and he launches himself forward, knife held at the ready.

"Loki!" Thor yells, stumbling backward as if it will do more than save him a second or two.

Carol runs after him, and she jumps on Loki's back, bringing him to his knees. She puts an arm around his neck, and Thor just knows that one wrong move will break it. He suspects that that's her goal.

"Stop!" Thor yells quickly. "Don't! Don't hurt him!"

Carol's grip holds tight. "What do you mean, don't hurt him?" she asks incredulously. "Are you paying any attention right now?"

Loki groans, furiously trashing about, and Carol only holds on tighter, wrapping her legs around her waist to keep him from throwing her off. "You killed him!" he screams. "You killed him!"

"Loki, what are you doing?" It's all he can think to say. And it's stupid – he knows it's stupid – but what else is he supposed to do? Loki's dead. He's supposed to be dead. He's not supposed to be here, wailing over the death of the man who just destroyed everything. He doesn't understand what's happening.

"You killed him!" Loki yells again.

Nebula pulls out her blaster. "Is somebody going to kill him or do I have to do it myself?"

"He's my brother!" Thor spits out.

The outcry of the other Avengers is loud, but Loki's louder. He shrieks, throwing Carol over his head and climbing back to his feet once more. "I am not your brother!"

Before Thor even knows what's happened, Loki stands in front of him, and he sinks his knife into his brother's chest. Thor cries out in pain, but, for the briefest moment, he feels... oddly ambivalent about it. This is far from the first time Loki's stabbed him, after all, and though the anger and the hostility in his eyes is new, this isn't. Loki knows how to stab, and Thor knows how to be stabbed. It's a mutual knowledge that marked their childhood.

But then he looks down, and he realizes that Loki didn't aim for the gut the way he always does, the way he knows he can.

He aimed for the heart.

"You killed my father," Loki growls. "Now I'll kill you."

He pulls the knife free, and Thor falls to his knees right there in front of him. As the world around him grows fuzzy, all he can do is look up at his brother, silent against his own will, and hope that somehow, in the midst of all this chaos, Loki realizes what he's done.

Nebula blasts a hole through his chest before he can.

"Loki!" He can barely choke out his brother's name. As Loki's body falls to the ground, Thor collapses, letting himself sprawl out over his body. "No, no, no, no," he whispers. "Loki, no. Loki..."

"Does anybody know what's happening right now?" Rhodey asks. "'Cause I'm lost."

Nebula sounds nothing short of smug when she says, "I've been wanting to do that for years."

Thor reaches for the blood-soaked knife that fell from his brother's hand, gripping it tightly in his own. "I'm sorry," he whispers. "I'm so, so sorry."

"Thor, he was trying to kill you," Natasha reminds him.

"I'm so, so sorry," Thor sobs. Each breath sends a shooting pain through his chest. He can feel the blood pouring out of him, but he doesn't care. He failed his brother. He failed him time and time again. Maybe this is what he deserves.

Natasha sighs and crouches down next to him. "Thor, we need to go," she says quietly. "You're bleeding out. I don't care if you're a god; you need medical attention, now."

"I'm not leaving him," Thor chokes out. "I'm not leaving him again."

"Thor, we have to go!" Natasha insists.

It's Steve who speaks next, all business in his tone. "Somebody get Thor on the ship. We have to go."

"I'm on it," Bruce says.

Thor can feel the metallic arms scooping him out, and as much as he fights, as much as he tries to yell at him to stop or to squirm free, he can't. He can feel himself fading, and the last thing he sees before the world disappears is his brother's corpse left behind.