Captain Hammer had always been more invulnerable than Billy thought. More invulnerable than any number of experiments could penetrate. No matter how many varied and devastating rays Billy had built to face him none of them had done more than knock him out for the count.
He'd forced him into numerous traps; he'd tried electrocution, fire, chemicals, toxic liquids, radiation, shrinking, various genetic mutation devices.
It was like the gods truly didn't want him to die. Billy had thought sometimes, in his more frustrated moments, that he was some sort of divine punishment just for him. That Captain Hammer was forever.
But he'd finally gotten used to the fact that Hammer couldn't die. He'd gotten used to the fact that there was no kryptonite. That he simply was, and pain was the best he would ever get.
He'd made causing Hammer pain part of his world.
Though nothing had ever seemed good enough.
The broken pieces of his shrink ray are scattered across the alley. There's a still a mark where Captain Hammer smashed it against the brickwork.
His grip is impossible but Billy's hands pull uselessly at his fingers anyway.
"It's justice, the good guys win, and I'm the good guy, I'm the hero. I'm always going to win."
It was an accident.
A completely unintentional mix of chemicals, giving his melting ray unintended properties. For all Billy's careful calculations it had been a freak accident that he never could have planned for. A freak accident that had nothing to do with his genius and everything to do with crazy random happenstance.
And now Captain Hammer was human.
Every part of him was simply human. With every pain and weakness that came with humanity. He was just like everyone else.
Now Captain Hammer could die.
"Don't," Billy says quietly, though it's barely more than a breath.
"Tell me you need me," Hammer's voice is flat, and he's too close, much too close, a solid line of heat and unfair strength and arrogant selfishness.
Hammer ignores the plea in his voice, there's a drag of rubber on the sore edge of his cheek, pulling him in just far enough, and Hammer's mouth is warm.
It doesn't hurt, Billy thinks it should.
Instead Hammer's hand is just still on the side of his face, holding him there, left in that space where Hammer can kiss him again. Can crush every angry breath back into his mouth.
Hammer doesn't let him go, not until he's forced him into stillness, mouth numb and hands shaking.
"Tell me you need me." Hammer demands, and there's something like desperation there.
But Billy won't give him that, he shakes his head, shakes it roughly.
Hammer was in the cold silence of his laboratory downstairs. Laid out behind the glass, the purple of new bruises on his skin, foreign like rot where Billy had never seen them before.
He'd been too stunned, too disbelieving, at first to gloat over his defeat, to stand over him, to be the one who won.
Instead he'd just stood there in stunned shock. If he'd ever planned for this, in his most optimistic of dreams, of victory over his nemesis. If he'd ever planned for it. It wouldn't have been like this.
If he'd ever written a speech he didn't remember it now.
Captain Hammer had been unnaturally still, back to the glass, curled in on himself in a way that felt protective of his newly vulnerable flesh. He was fragile now, fragile in a way he'd never been. Fragile even in a way Billy had never been. Too used to the wet brutality of violence and its consequences.
Captain Hammer was new, new enough that Billy could press bruises across every inch of his skin if he wanted to. He could break it and watch him bleed, watch him breathe through bloody teeth, spit red on the floor, where it would spread and stain his hands. Over and over.
Part of Billy had wanted that.
He'd wanted it in a way that had threatened to eat through him like poison.
But at the same time it terrified him.
He didn't want to be the sort of person who could tear a man apart.
Even Captain Hammer.
Especially Captain Hammer.
"That," Captain Hammer stops short of actually touching him, though the hand gesture is forceful. "I didn't do that."
Billy frowns, eyes the finger from an inch away in utter bewilderment for a long second, before he remembers the mark on his jaw, half cut and half bruise, that stings like madness every time he yawns.
"No," Billy tells him. "No you didn't."
There's confused anger somewhere there that Hammer clearly isn't quite sure what to do with.
"Tell me who did," he demands.
"Why, so you can congratulate them?"
"Who hit you?" Hammer asks again. A fierce edge to his voice this time, the edge that Billy only ever hears when Hammer's doing something righteous.
"Don't you dare pretend that you care." Billy's voice is floating closer to hurt than angry mockery and he doesn't mean it to. He doesn't want that thread that feels vulnerable in his voice.
Hammer catches a handful of his shirt before he can step back. Fabric tangled in his fist, and the edge of material is high enough to expose the angry purple painted over the bottom of his ribs.
Hammer stills, other hand turning him, twisting his body round, pulling the length of it close to his fingers.
He eases Billy's shirt higher; reaches out, like he means to touch, as if he's fascinated by the colour of it. Billy breathes in, pulls his skin away from Hammer's fingers. Though not far enough, not quite far enough.
Billy flinches when his thumb presses against the mark.
Hammer surprises him when he does as he'd told.
"That one you did," he accuses quietly, but his mouth feels like it's full of sand, and then Captain Hammer's hand moves again, and doesn't stop moving. Doesn't stop sliding under the fabric of his shirt in curious restless movements-
It was a choice, it was the same choice he'd had at the beginning. The same choice he'd made years ago, before he knew it was impossible. While he still thought it was impossible.
It was a choice he'd accepted he couldn't have, and now here it was, suddenly offered to him again.
But it wasn't the same.
Kill Captain Hammer.
Make this everything, make this his whole life.
It meant digging the knife in and cutting out the last of the scar tissue, leaving himself empty and clean.
Leave nothing but Dr. Horrible behind.
Billy wondered how a mask became a man. Something that had started out as words and a coat and a laugh had spread like cancer and consumed him from the inside. And he never said no, he never once said no.
He thought it should be terrifying but he found himself strangely calm.
If he killed Captain Hammer he thought that might be the end of him too. The last link to who he'd been, who he used to be. The parts of him that still remembered what it was like to be something other than this.
When he'd still had dreams.
Before people started dying and he stopped caring, piece by piece.
A part of him was certain that thought was stupid and melodramatic.
The rest of him wasn't so sure.
But he knew one thing for certain. Without Captain Hammer there was no need for him any more. Everything after this would be purpose and fury.
For the first time in a long time, there was nothing in his head but silence.
"You make it easy you know." Hammer's voice pushes into his skin, it's not just arrogance and mockery any more. Though Billy almost wishes it was. He thinks this is worse. "I don't even have to push, you just let me."
"Don't-" Billy starts.
Hammer presses bare fingers over his mouth, not quite too hard but teetering close to the edge, and then Hammer's weight shifts, presses down, heavier than he has any right to be.
Billy's sure Captain Hammer only ever takes his gloves off for this. To feel the bruises he makes, pressed deeper into bare skin than they ever are through cloth. To prove that he can own him when they put the costumes aside. That Billy can't hide. He can't ever hide.
He's found a new way to hurt him, and this time Billy lets him. He hates himself for it but it's easier to give in than to make it all stop.
So he lets Hammer push him where he wants, thighs cold against the heat of Hammer's bare waist.
Every push of his fingers is obscene, long, slow presses that linger, that try and push noises out of his throat, until impatience and greed force them to stop. Hammer's breath turns low and ragged, before becoming a thick satisfied noise when Billy doesn't protest, doesn't try and stop him, he lets Hammer slide all the way into him. It's a ragged too-hard push that he thinks he deserves.
Hammer's fingers slip free from his mouth and shift to his waist instead, catch there and pull on every push.
Billy says nothing at all.
Maybe he was never supposed to win.
It was a choice.
A choice that would change everything.
Billy sat in the chair for a long time.