Sherlock was flitting around the crime scene, the tails of his coat flapping like the wings of a hummingbird. He was a wonder to watch, poetry in motion. The detective bobbed and wove hither and yon, now bending to examine dark patches on the pathway, now stretching to feel the rough surface next to a window.
It happened before John could stop him. Sherlock ran his hand along the strange blue substance on the freezing cold fire escape, then... he licked it. When he went to pull back, he couldn't. His tongue was frozen to the fire escape.
"Don! I dan't dood! I'n duck!"
Sherlock's arms were flailing madly, mobile phones were snapping photos and the only person not laughing was John, though that was a near thing.
The doctor grabbed Greg's coffee that was still steaming in the cold. "Sherlock!" he snapped loudly to get the detective's attention. The flailing stopped. "I'm going to pour coffee over over your tongue and you pull back gradually."
Slowly, Sherlock's tongue came loose. The detective straightened up, shot a glare around at everyone and flicked up his collar. With one last round of glares, he stalked quickly from the scene.
Greg looked at the doctor. "John, mate. Want to crash at mine tonight?"
John nodded thoughtfully. "You know, that idea is absolutely brilliant."