Sally tugged on the hem of her shirt nervously.

She wasn't, and never would be, entirely comfortable with this aspect of her job. But it was part of it, no matter how... distasteful she found it.

She has been undercover before, although admittedly, not for anything like this. Those had been... minor operations, and she was always with someone, or more than one person.

Here, she was alone. In a not so great neighbourhood. And practically exposed for all the world to see. She hoped that did not include the freak. Because as disinterested as he seemed in sex, it didn't matter. She was not out here pretending to whore herself on a corner so he could watch.

But the freak was the one who figured out their guy picked up a girl from this corner every Thursday night, took her home, and killed her when she was finished. However the hell he did that, she has no clue. But Lestrade seemed impressed, and the freak had explained it or something, and he was convinced.

John had once told her something that Sherlock had said about his so called 'homeless network'.

Sherlock had been going on about how he would pay them for information. John had asked if it was a sort of a 'scratch their back relationship', and Sherlock had butted in saying that yes, and then he disinfected himself.

Sally smiled. That was sort of how she felt right now. Like after this whole ordeal was done with, she would have to go home and bathe in bleach or scorch the top couple layers of her skin off. She felt dirty, and suspected that no amount of scrubbing would get rid of that feeling before it was ready to go.

The car that freak had determined belonged to their suspect probably though some stupid thing like dog crap on a tyre or paint flecks pulled up alongside her.

She took a deep breath before sliding into her role. She leaned into the window seductively.

"Looking for someone?"

The car smelled like smoke and alcohol and... something that Sally didn't want to know what it was, even though she had a pretty good idea. She forced herself to smile, in a way that she hoped was attractive. She wasn't very good at this.

He scrutinized her, like she was a piece of meat at the butcher's. She hated him instantly, and would have even if he hadn't killed four girls already.

He seemed to approve, because he instructed her to get in the seat next to him with a nod of his head.

She slunk around to the other side of the car, and slouched into the seat. He turned to face her, and threw his left arm over her shoulders, pulling her closer. His hand moved lower. He pulled her closer still. Sally worked hard on not being disgusted. It will all be over soon. He moved in to kiss her. She could smell his breath, much like his car, except with something additional that she didn't recognize. Or maybe she did. Oh she did. She knew it all too well, it practically dripped off the other girls in her neighbourhood when she was little and wanted to play with them. Hate.

Lestrade and his men came out of the woodwork and had the suspect surrounded, guns pointed, before he could so much as think. Not like he did too much of that. Sally shrugged out of his embrace. He looked mad. Serves the bastard right.

She was unsteady. Unsure. Momentarily thrust back into her childhood, a place she never wanted to return to. After she finished up at the scene, Sally went home and took a shower that was far hotter than would be comfortable for anyone. She scrubbed herself raw, not once, but twice.

But she was right. She still didn't feel clean.