It started on a dull, damp Friday night in October. Sam was making his way back to his flat, leaving the rest of CID to their increasingly raucous drinking and darts. He could foresee a dart to the face for someone before long, and he didn't want to be around when it happened.

Well, maybe it depended on whose face...

He shut that thought down. He was above that kind of petty spite - it was bad for his karma. Or his chi. Or both, possibly.

He shoved his hands further into his pockets and hunched his shoulders against the rain. He'd popped the collar on his jacket but it wouldn't stay put, and he'd just been getting wetter and colder trying to hold it in place. So he hunched, and hoped this would offer some meagre improvement, or at least would stop the rain running down his neck. He could already feel little rivulets running across his scalp, where his short hair had soaked right through. He thought longingly of home - real home, not the ever-cold and soulless bedsit he was reluctantly trudging towards now. Proper home, with central heating, and a proper duvet. And gin.

He heaved an unheard sigh, eyes watching the pavement underfoot as he skirted round the worst of the puddles. The stuttering streetlights cast their orange glow, drawing the colours out of everything, making his shadow lengthen and shorten. The streets were quiet at this time of night - everyone was settled in for the evening one way or another; fish suppers in front of the telly or pints of lager down the local. It wasn't a night to be out in.

As this crossed Sam's mind, and as he began to ask himself why exactly he was out in it, then, a movement drew his eye. Another pedestrian, a girl, had come round the corner from a side street, and was now making her way along the other side of the road. Her bobbed hair and the fur trim on her coat were both flattened with the rain, and she, too, had her hands deep in her pockets and her chin tucked in, to keep out the worst of the cold. Her bag swung from one shoulder, gently bouncing off her hip as she made her determined way onwards. She was walking towards Sam, but with her head down and, presumably, her mind on getting wherever she was going as fast as she could, she hadn't seen him. Her flares dragged on the ground, sodden wet, adding a swishing sound to her quick footsteps. Sam began to look away again, when he noticed that she wasn't alone. Emerging slowly around the same corner was a tall man, with a scarf drawn up over his face. He, too, had his hands in his pockets - no, wait. Just one hand in his pocket. And he wasn't hunched over, as Sam and the girl were; he had his head up, moving carefully and steadily. His eyes were fixed on the woman in front of him.

Sam was between streetlights, just out of the pool of light from either, and without thinking about it, he stopped. He watched the newcomer to the scene, his copper's instinct thoroughly roused and sniffing the air.

You're off duty, he thought. He batted the idea away - a good copper was never, ever off duty. Never.

What's it to you? One more mugging in Imaginary Manchester. So what?

As always, when an intrusive thought like this came along, he felt a stab of guilt, made all the more pronounced by the fact that this inner voice was so beguiling. He just wanted to get back to his miserable excuse for a flat, have a glass of wine and go to bed. He just wanted to get out of these wet clothes - his shirt was sticking to his chest, where his jacket opened at the front. He just wanted a quiet night, for once, with no voices from the TV, no Gene Hunt breaking in his front door and no bad dreams. And that also meant no playing the knight in shining armour.

It wasn't fair. It just wasn't fair.

As he tried to pretend he wasn't thinking any of this, the man on the other side of the street had edged closer to the girl in front of him. His longer stride was making it easy for him to catch up; there was no need for him to run, no heavy footfalls to give him away. He hadn't noticed that he was being observed; even if there had been a spotlight on him, Sam suspected the guy was too focussed to see anything but his intended victim.

Leave it. Just keep walking.

Sam felt his muscles twitch, as though to do exactly that, but he won the battle with himself and stayed put. Both woman and man had passed him, now, and as he turned slightly to continue watching, he saw the opening of an alleyway ahead of them. In a flash he knew what was coming - the woman was going to turn down that alley (that dark, unsafe alley), and the mugger was going to have his chance.

Stupid bitch.

Sam's eyes actually widened - he couldn't believe he would think that. He wasn't that guy; he was a feminist, for God's sake. And a police officer - fighting crime, protecting people, that was what he did. What he was.

In front of him, the scenario started to play out exactly as he'd predicted, and the girl with the bobbed hair turned into the alleyway and out of sight. Her unseen consort, not far behind her now, followed suit.

Before he could have any further upsetting thoughts, Sam set off at a jog across the road. Now that he was in motion, his mind was clear and sharp; this was not only the right thing to do, it was the only possible thing. He increased his jog to a sprint, realising that he might actually have left it too late to intervene, the thought making his heart stutter and increasing his sense of urgency.

He barrelled in to the narrow lane after the pair, hearing himself shout 'Oi! P'lice!'. That might not exactly be in the rule book, announcing himself like that, but he'd picked up a few bad habits since waking up here. He screeched to a halt as he saw the two figures just ahead. They'd hardly got any distance into the alley before the man had made his move.

The scene in front of him was just as he feared, though not as bad as it could have been; the girl had her back pressed against one of the mossy brick walls, the mugger in front of her, standing far too close - maybe a mugging wasn't all he'd had in mind, then. Sam felt a flare of rage, which he contained as best he could.

'Step away,' he said, firmly and clearly, standing silhouetted against the entrance to the alley. As his eyes adjusted, he could see that the assailant had taken his hand from his pocket to reveal a short, broad bladed knife, which he was holding in an underhand grip at his victim's stomach. The girl had been taking off her jewellery - the gold of a ring and bracelet glinted in what little light there was, as she held them out to him in a cupped hand. Her bag lay on the ground next to them, where it had either fallen from her shoulder or been grabbed and dropped.

The mugger seemed too shocked at Sam's appearance to do anything, and both he and the woman stood in a frozen tableau, staring at the interloper.

'Step away, now,' Sam repeated, voice still strong. He began to walk towards them, his hands raised and spread open in that universal gesture.

'Fuck off, pig.' The man's voice was muted by the scarf he still wore over his face, but Sam had no trouble understanding him. Another spike of anger needled at him, but outwardly he remained calm. He took another step forward.

'Drop your weapon.' He had kept his hands up - he'd nothing to threaten the guy with, anyway, he realised now. His gun was back at the station, locked away safely, and he didn't carry a stick these days. This was definitely an oversight.

The would-be mugger had turned to face him now. 'I said, fuck off.' Sam could hear a little fear in the muffled voice, but not as much as he'd have liked. A little fear could make a person more desperate, more dangerous. This guy was a fighter, not a runner, and he was armed. He'd taken a step back, away from the girl, and brought the knife around with him, holding it low by his side in a clenched fist. Sam found that he wanted to wet his lips, some of his certainty and confidence draining away in the face of such determined opposition. Instead, he took another step forward, bringing him almost within arm's reach.

'Drop your weapon, and step away.'

His own voice remained steady, and he lowered his arms to his sides again, preparing for what looked like an inevitable fight. This time the mugger actually gave a derisive snort behind his improvised mask, then took a sudden and unexpected lunge forward. Sam had no time to react - it had happened so quickly - and he grunted as he was punched in the stomach. He struggled to stay upright, and brought his own fist up and round, catching his assailant in the jaw. He was treated to a second, harder punch to the gut that left him winded, and he dropped to his knees, raising his arms to cover his head while he tried to catch his breath. He felt a kick land on his shoulder, driving him completely to the ground, flat on his back on the wet cobbles. He knew he had to get back up and defend himself, and the woman, but even as he thought this he heard running footsteps. He risked a look from behind his arms, expecting to see the woman taking the opportunity to run, and glad that there would be one less thing to worry about. Instead, she was standing over him, her face glowing white in the gloom, her mouth open.

Sam pushed himself up to a sitting position, one knee bent, gasping at the unexpected pain but forcing it to the back of his mind for now.

'Are you alright?' he asked her, looking around to make sure they were really alone. He couldn't believe the guy had run off like that. Thank God he had, it had started to look serious there. When the woman didn't answer him, he turned his face back to hers.

'Are you alright?' he asked again. She seemed to be too shaken to speak, though Sam noticed that her hands were working on putting her jewellery back on. He felt a grim satisfaction at that; the guy hadn't got anything. He'd been just in time to stop him.

The woman had begun to shake her head, her mouth moving as though to form words.

'It's alright,' Sam said, deciding that shock was probably setting in. 'Come on, we'll get you down the station, someone can take you home from there.'

'I'm sorry,' she said, in a breathless rush.

Sam smiled up at her, as reassuringly as possible for a man with his arse in a puddle. 'You're fine. Everything's going to be fine.' He pushed himself up with one hand, bringing his second knee up to lever himself off the ground. The pain was immediate, and enormous - there was no way to ignore it this time. The smile froze on his face, then turned to a grimace as he collapsed to the ground again.

The girl's face appeared overhead, hazy in the rain.

'I'm sorry,' she whispered again. 'I'm so sorry.' She ducked out of sight, and Sam heard her pick up her bag - he couldn't turn his head to look. The pain was leaving him weak. He dragged a hand that weighed a ton to his stomach, and when it landed there was another burst of agony, like fireworks behind his eyes, and his head swam.

She was standing next to him again, the girl, and looking down with her pale face and wide eyes.

'I'm sorry.' This time it was more of a whimper, and she turned abruptly and ran off, back towards the street.

'Wait...' Sam tried to shout after her, but she didn't hesitate. He was starting to feel sick, and tried again to sit up. This time he couldn't even make it that far; the pain was too great, the strength had been drained from his arms. Lying on the cold cement, he held his hand up to his face. It took all the effort he had in him, and when he saw the viscous smear of red across his fingers, swirling and running down to his palm and dripping on to his shirt, he finally accepted the truth.

He let his hand drop to the ground, his knuckles clattering against the stone in a way that would surely have been painful any other time. He felt cold, clammy. He couldn't catch his breath. He was going to die here, in an alleyway, all for trying to help some thankless bitch. This time it didn't even occur to him to try and unthink it. He hated her. He was bleeding to death, alone in the dark, and it was all her fault.

All. Her. Fucking. Fault.

The anger tasted bitter in his mouth.

He wondered if, after he died, he would wake up at home again. Maybe. Did he even want to? His thoughts of earlier, of central heating and gin and tonic, seemed shallow and unimportant. Everything seemed meaningless. The spinning world seemed to tilt on its axis, and as the darkness closed in, he shut his eyes.

Footsteps in the dark. A strong arm behind his head. A nipping at his neck, sharp and painless at the same time, disconnected from him. Then, someone making him drink, and wanting to at first but soon trying to turn away. It wasn't water. He didn't like it. They insisted, holding his head and forcing him. It was hot, and cloying. Salty and metallic, like when his mum used to make him eat his liver and he'd cried over it when he was little, cried because it was so horrible, but she'd cajoled him and convinced him and, when it came to it, made him sit at the table for hours as it grew cold and congealed on the plate, even worse than when it was hot, and she still made him eat it.

'You want to grow up big and strong, don't you Sammy?'

He swallowed, the irony taste coating his mouth and throat like medicine, churning his stomach. The pressure on his head let up a little, and he drew in a huge, gasping breath, eyes squeezed shut, before he was drawn back in, back to the source, and this time he gulped more readily. And somehow, it wasn't so bad any more. He wanted another sip, and after one more nobody was holding his head any more and he was drinking freely, feeling the warmth run back into his cold body, stopping only to gasp in air when he had to. Then, all too soon, he was pushed away, and he gave a wordless moan, trying to reach out, but his arms still felt heavy, weak, lifeless.

'Sleep now.' The voice was cultured, and even with so few words, oddly persuasive. He felt himself lifted from the ground, and then he let the black return.