See end for notes.
For several eternal seconds after he finds Jane's body, Thor doesn't comprehend what he sees.
She is lying on her back, sightless eyes wide with terror, covered in her own blood. The source is clear: a wound gapes open under her jaw, and above it her face is as pale as marble.
It is not possible. It is not possible. He'd said he would find a way to save everyone and he'd brought her here for a reason and she'd trusted him and this cannot have happened, not now, not already—
He is so lost in denial that he barely realizes he has fallen to his knees by her body, and at first he doesn't see the knife still lying next to her head. When he does, it takes him much longer than it should to recognize it.
Loki's knife. It is Loki's knife.
For a moment he is stone still, unable to see or move or think, and then a sound behind him breaks through his shock: the quiet scrape of boots over gritty soil as someone tries to back away.
Suddenly he can feel again, only he feels nothing but rage—not the heady berserker fury in the heat of battle, this rage is just as blinding and yet it seems to give deadly, razor-sharp clarity. It is cold, cold, cold, like ice, like Jotunheim, like the Frost Giant he once called brother.
He is conscious of only one distinct thought: Enough.
Thor rises and turns in one quick motion. Loki is several paces away, tensed to flee, but between the jagged, towering rocks all around them and the fact that Thor can fly, he has nowhere to go. At Thor's look he raises his hands, palms out in as much of a placating gesture as he can make with his wrists bound together. "I didn't do this," he says. "Thor, wait, for once in your life listen to me—"
Thor is far, far beyond listening. He advances on Loki, Mjolnir heavy in his hand. "You will never be satisfied, will you? You would take everything from me—my family, my throne, even the woman I love—"
"I didn't," Loki insists, still trying to retreat. He stumbles over a rock and barely catches himself. "I haven't been out of your sight—stop and think, this is what Malekith wants!"
"No more." Thor is so cold he burns, fingers so tight on Mjolnir's handle that he can't feel them. "No more. I said that when you betrayed me, I would kill you. I keep my word."
Loki stumbles again, his expression shifting as if he hadn't believed, and he tries to sneer but it doesn't look quite right. Thor notes distantly that Loki's outstretched hands have started to shake. "You would attack me when I am bound and unable even to defend myself? How very honorable of you. Odin would be proud."
Thor doesn't slow. "You care nothing for honor. Why should I?"
"Thor," Loki says, and Thor doesn't want to hear it, doesn't want to listen to one single more lie, will not. He swings Mjolnir without any conscious thought, and the blow sends Loki flying back to slam against the cliff face with stunning force and collapse to the ground. He struggles to rise as Thor strides toward him, only his arms don't want to take his weight, and Thor realizes just as distantly that with his upraised hands in the way, his brother (not his brother) likely already has broken bones from the first blow. He should feel pleased about this, he thinks, or dismayed, or something, but he only feels the unrelenting cold.
Loki hasn't even managed to make it to his knees by the time Thor reaches him, and when he looks up his face is tight with pain and genuine fear and something else that Thor doesn't bother to identify. He is aware of a dully vicious satisfaction that finally, finally, after all the death and havoc and terror this Jotun has caused, finally he himself is helpless and afraid, with nothing to hope for but mercy he has no reason to expect. (A faint thought at the back of Thor's mind says no, this cannot be right, Loki is well acquainted with fear and despair, perhaps more than anyone ever guessed—but this too withers to nothing in the icestorm of rage.)
"No," Loki says, "Thor, no," and then in desperation, "brother, please—" and suddenly Mjolnir isn't nearly personal enough. The rage consumes him. He isn't aware of dropping the hammer, shoving Loki onto his back, or pinning him to the dirt, but then his hands close tight around Loki's throat and this feels right.
Loki jerks under him, eyes widening in panic, and Thor squeezes harder, closing him off completely, feeling him struggle futilely for air as his frantic pulse thrums against Thor's fingers.
This is right. This is right.
Loki tries to twist away, tries to pull his hands up to claw at Thor's face, tries to kick him off, but he doesn't have the leverage, definitely doesn't have the strength, and he's already weakening, mouth gasping open for a last breath he's never going to get. There's nothing he can do to get free, nothing he can do to stop this, and Thor knows this with the same certainty that he knows Mjolnir is his, that Heimdall sees everything, that the All-father is wise
(that Loki is and always has been his brother, no matter what else happens, and all his other certainties have failed)
He is vaguely aware that Loki is barely fighting him, still shoving desperately but ineffectually at Thor's immovable chest with his trapped, bound, and broken hands, and another faint thought intrudes: he is not doing magic. He is not doing magic to free himself (Thor is not clutching empty air) or strike back, Thor is choking him and he is still here and surely that means something?
(if he isn't doing magic to save himself it means he can't, his bonds haven't failed, he can't have used magic to slip away and murder Jane)
(stop this stop you have to stop)
The rage is icy poison coursing through his veins and he cannot listen, cannot stop.
So he does not hear the voice calling his name or the running footsteps, can think of nothing but his crushing grip on Loki's neck and the way he can feel the strength draining from his not-brother's body, until someone actually grabs his shoulder and yells "Thor!" right into his ear. He doesn't let go, but he has the presence of mind to turn his head and look, and the sight of Jane's stricken face inches from his own is as great a shock as finding her corpse.
It's a trick, it has to be a trick, except Loki's close to passing out and Thor can feel Jane's hand on his bare arm, warm and solid and real. He yanks back his hands as if he's been burnt and scrambles to his feet, and Loki takes a great grasp of air that turns into a painful, wracking cough.
Thor takes a step back, then another, and all the ice is melting and nothing makes sense. Tentatively he reaches out, fingers barely brushing Jane's jaw. "Thor," she says, staring at him, "what happened?"
It takes him a moment to find his voice. "I thought you dead. I saw you—" He looks then, and there is no body, no blood, no knife, just the sound of Loki's ragged breathing.
"I was trapped," Jane is saying, "I don't know what happened but I couldn't get to you," and Thor can't listen anymore, his gaze drawn against his will back to Loki, curled on the ground and shaking. Slowly he pushes himself upright, and he's not looking at either of them, but Thor catches sight of his face and he doesn't even look angry, just…resigned. Unsurprised. And Thor knows that if any chance existed of bringing his brother back, this time he is the one who has broken it beyond repair.
I don't even know what this is, honestly. It's certainly not what I want to see in Thor 2, nor what I'm expecting to see, and it was just inspired by some anon's suggestion on LadyCharity's Tumblr that Thor might actually try to kill Loki in this movie after believing, wrongly, that Loki's betrayed him. In a lot of ways I think I wrote this to reassure myself that this sort of thing was really unlikely to happen in canon, because Thor feels pretty OOC here to me, compared to the way I understand the character (for that matter, Loki's probably pretty OOC too). Considering I'm more likely to write fix-it fic on some level so I can cling to my own headcanon if actual canon doesn't satisfy me or quite make sense, the fact that I've written speculation fic at all—especially of a situation I don't want or expect to see—is pretty weird, but what are you gonna do.
At the time I'm posting this, I'm going to see TDW tonight, but I finished the actual writing around Oct. 18.