A/N: So, these were originally supposed to go in my default drabble collection, Montage. However, they sort of...grew, and are now four drabbles and a ficlet. I've never written darkfic before, so all comments and suggestions are welcome!
He works constantly—not eating, resting only when he falls asleep at the worktable, his head pillowed on frantically scribbled notes and half-drawn plans.
No one bothers him. His manic intensity has scared off even Moist, and now the henchman only comes down to the lab every other day to bring him coffee and a sandwich that is left untouched on the plate.
His is slowly disintegrating inside, and knows it, but he doesn't care. The only thing that matters now is Her. He has to save her. That's something Dr. Horrible and Billy agree on: they have to.
Breath. One breath, then two, melting into a steady, impossible rhythm.
The anticipation of this moment has kept him going for weeks-- imagining her first tentative breaths, her eyes opening and seeing him for the first time. Now it's here, and he just feels…drained.
He hadn't even noticed her waking up. He tries to smile at her, but the muscles don't work properly.
"What happened?" She's looking around, her initial confusion edging quickly towards fear.
"There was…an accident," he stammers. "You were…hurt, but you're better now." He smiles again, and this time it almost seems real. "Everything's better now."
She wishes she could believe him. She tells herself she's happier than she's ever been. She's secure and comfortable, and has a devoted lover who saved her life.
But sometimes, she sees him looking at her, and he's not the man who holds her when the nightmares come, or buys her frozen yoghurt on his way home from work—she still doesn't know what he does. He's become cold and emotionless, a scientist studying a particularly clever experiment, and it's then she wonders if he's what haunts the dreams that wake her screaming in the night.
Maybe she should be dead.
Over time, she does actually become happy. The nightmares are gone, and the phantom pains in her chest have subsided. Somehow, when she finally discovers that her sweet Billy is the evil Dr. Horrible, it isn't the shock she'd have expected, and she realizes she's known all along, even if she hasn't let herself believe it.
But then she sees that Billy is weak. His obsessive love for her makes him less powerful, keeps him embarrassingly moral and blindsided. How can he change the world like this? He's slowly loosing it. Perhaps he should be replaced. She wouldn't be weak.
It is far, far too easy to kill him.
She's become too much like him, taking in the cruelty, the detachment, the casual disregard for life. Penny can feel it rising inside her, and she wonders for the first time if evil is in everyone's heart as well as good. In the end, she doesn't care, and that's when she knows it's too late.
He never sees it coming. In the end, it isn't the ELE or Captain Hammer, or some experiment gone wrong that finishes him—it's a kitchen knife in the hands of someone who once loved him and with time has become too close a match
There is an empty seat at the table now. She takes it, drawing the goggles over her eyes, and she isn't Penny anymore. She is Horrible. Maybe she's always been.