Rain had left London slick and grey by the time you arrived, the pavement outside the cordoned building shining under the wash of police lights. A cluster of uniforms stood at the mouth of the alley, muttering into radios, shoulders hunched against the cold.

You were late.

Not your fault, technically. Lestrade had been late collecting you from Bart’s, and then spent half the drive apologising in that distracted, half-breathless way of his while also refusing to tell you anything useful beyond, It’s complicated and He’s in one of his moods, so just—ignore him if he says anything.

He.

As if that narrowed it down.

Of course it had, in the end. There was only one he in London people spoke about like that.

Sherlock Holmes.

You had heard enough over the past year to build a dozen different versions of him in your head. Brilliant. Impossible. Rude. Useful. Unbearable. Scotland Yard’s pet genius. The only man who could walk onto a crime scene and make trained detectives look like schoolboys with notebooks. You had never met him, but you knew the stories.

And, quietly, you had been a little impressed by them.

You kept that to yourself.

Lestrade ducked under the tape and jerked his head for you to follow. “Right,” he said, already sounding tired, “before he starts—you’re here because John’s down with some sort of virus and I need a medical head on scene before Sherlock starts poking at things he shouldn’t.”

“I heard that,” said a voice from somewhere ahead.

You looked up.

He was standing near the far end of the alley, just beyond the reach of the nearest flashing light, long and dark against the brick wall like he’d been placed there for effect. Tall—more than tall, really, all sharp angles and restless stillness—wrapped in a heavy black coat with the collar turned up against the cold, a dark blue scarf falling loose at his throat. Beneath it, the clean lines of a suit. Pale skin. Dark curls, slightly untidy in a way that only made his features seem sharper. High cheekbones. A mouth set in something close to impatience. And eyes—light, difficult to place in the shifting glow, somewhere between blue and grey and green—already on you.

Not lingering.

Observing.

It was quick, but precise. His gaze moved from your shoes to the hem of your coat, your ID badge, your hands, the faint ink mark near your thumb, the crease in your cuff from dressing too quickly. Then back to your face.

You had the distinct impression he had already noted more than was comfortable.

Lestrade sighed, gesturing between you. “Sherlock, this is—”

“Bart’s,” Sherlock said over him, still looking at you. “Medical staff. Not entirely new to this, though you’ve not done much fieldwork yet. You hesitated before coming, then decided it was worth it.”

A brief pause.

“And you hurried.”

Lestrade closed his eyes. “Sherlock—”

“No, let’s have this bit, it’s the only interesting thing that’s happened in twenty minutes.”

His attention didn’t waver. Up close, it was sharper—more focused, every line of him drawn tight with impatience. When he concentrated, the restlessness seemed to fall away into something still and exact.

He gave you one last quick look over.

Then, flatly, “I don’t need help.”

The alley seemed to go quieter around the three of you.

Lestrade exhaled through his nose. “That wasn’t a suggestion.”

Sherlock ignored him.

“Unless,” he said, tone dry, “you’re planning to contribute something more useful than standing there deciding whether I’m taller than you expected.”

A slight tilt of his head.

“Well?”