The worst of the bleeding has passed, but the pain still thunders on, pulsing in time with her heartbeat, lancing her vision with red.
Rose ignores it.
"Please," she says through gritted teeth. She tries to stand up, but even her non-injured leg won't hold her weight, trembling violently with every tense of her muscles. She immediately slides back down the rain-slicked wall, landing on the ground with a groan. "Doctor…"
"Not now, Rose."
"Doctor, please. Look at me," Rose gasps out. "Just breathe, okay? Just think about this."
"Oh, I've thought about it," the Doctor replies, and Rose could almost believe how normal he sounds, how casual, if it wasn't for the revolver in his hand. She can just barely make it out, its edges glinting in the yellow streetlight. "Thought about it quite a lot, actually. It's funny just how much time you have to think about something while you're fashioning a makeshift tourniquet so your partner doesn't bleed out into the alleyway."
He spares a millisecond's worth of a glance back at her. "How's it holding up, by the way?"
"Bleeding's mostly stopped. I'm fine, really."
He shakes his head, and even though his back is turned to her, Rose can picture the look on his face right now, how the lines of his mouth have tightened, how his eyes have gone hard.
"No," the Doctor says quietly. "You're not fine."
"I'm not dead. That counts for something, doesn't it?"
"Don't do that."
"Don't do what? Try to talk you out of doing something you'll regret?"
The Doctor doesn't reply. The unconscious lump in front of him has begun to stir, drawing each and every ounce of his attention. The Doctor's arm, frozen in a rigid line, has not moved from its position, pointing the barrel of the revolver directly at the prone form. He's locked onto them like the needle of some kind of morbid compass.
Rose closes her eyes against the pain, but that's almost worse; without any visual stimuli to offer a distraction, blood-red bleats behind her eyelids and nausea threatens to overwhelm her. "The rest of the team will catch up soon," she says, fighting to keep her voice level. "They'll contain him."
The Doctor huffs out a disbelieving laugh. "Right, because that worked so well last time."
"We know better this time. We've adapted."
"And the next time he hurts someone? The next time he kills? Who will bear some of that responsibility, whose hands will share that blood?"
"No one," Rose argues, shaking her head. "No one but him. He's responsible for his own actions, Doctor."
"And I'm responsible for mine," he says darkly.
Rose winces at the cold flurry of raindrops that splatter down on her head and face. "Listen," she says, pleading. "I understand where you're coming from. All right? I've felt it myself. I've been there before. Something bad happens, and you've got to fix it, make it better, somehow. And yes," she continues, pitching her voice over the loud plink-plink-splat of the rain that descends on them, soaking their hair and clothes and running between the cobblestones in rivulets stained pink, "he's probably a worthless waste of space. He probably can't be redeemed. But I don't care about him, Doctor. I care about you. I care about what's going to happen to you, if you go through with this."
The Doctor's shoulders rise and fall, steady but heaving, and Rose knows his breathing has gone rough. She hears a click and she knows exactly what it is: the Doctor has pulled the hammer back.
"It's funny, isn't it?" the Doctor asks, his voice shaking. "Funny how a little bit of humanity can really clarify your perspective on things. Like superheroes, for example."
Surprised, Rose is tempted to ask what the hell that's got to do with anything, but she stays silent.
"Superman, Batman, Daredevil, the majority of them. They don't kill. They don't do it, because according to their logic, that would make them just as terrible as the villains they're trying to stop," the Doctor says, and his entire frame is shaking now, trembling from the cold and the wet and everything trapped and clawing just beneath the surface of his skin. "If any of them killed, that would make them a monster.
"At least, that's how the stories' internal logic works," he says, shaking his head to clear the rain out of his eyes. "But really, we all know why they're written that way: because those stories, like so many others, are meant to appeal to children. And we can't sully children's minds with images of their heroes committing acts of brutal violence. We don't tell children that death is the answer. Nor should we. But there's an ugly practical side to all of this that no one wants to discuss: how many lives would have been spared if Superman just smashed Lex Luthor's head into the pavement? If Batman just snapped the Joker's neck? Isn't the piety of a superhero strangely selfish, if you really think about it? Do the villains really deserve to live, just because a hero doesn't want to get their precious hands dirty? Do the lives of those people—the real monsters—really outweigh the lives of dozens, hundreds, thousands of others?"
"Doctor, please, just take a step back and think about this," Rose begs. "You were fine with hunt-and-capture until he hurt me. You didn't feel this way when he killed those other people. You're just angry because he tried to kill me."
The Doctor draws in a long, shivering breath, and for a moment, suspended in breathless anticipation amongst the thickening rain, Rose thinks maybe he listened to her.
"You're wrong, Rose," he says, as the air around them fills with the sound of Torchwood sirens, loud and sharp and shrill. "It's not about fixing things. It's about punishment where punishment is due."
When he speaks again, Rose can hear the tears in his voice.
"I'm not a superhero."
He pulls the trigger.