"It's the third one in two weeks." Dr. Anderson prodded the corpse with some distaste.

"Completely drained of blood?" Sherlock was so curious he forget to be offensive.

"Pretty much. Yes."

"How?" John was examining the corpse for puncture wounds around the major arteries. Anderson shrugged. There were no wounds. Anywhere.

"And I don't understand where all the blood has gone. I mean, how do you make off with nine pints of blood? Why would you make off with nine pints of blood?" Anderson looked genuinely distressed. John stood and patted his arm.

"What do we know about the other two?" Sherlock addressed no one in particular but expected an answer all the same. "What links these three men?"

"They're all men." Anderson was trying to be helpful for once. Failing miserably, but the thought was there. Sherlock ignored him.

"Right. Well that's something." John looked at the pale corpse. "All men."

"Get me the files. We'll be at Baker Street. Tell LeStrade. In fact where is he?"

"At the Yard." Anderson squeaked before hurrying from the scene in the general direction of vomit. It was a bit not good, John thought to himself. But then he'd seen worse.

"Idiot!" Sherlock said to no one in particular as he stalked off, leaving the drained body to be removed from the scene.

...

Greg smelt Sherlock before he heard him, or saw him A very particular smell. Not unpleasant. But surprisingly not the sensuous smell his exquisite outward appearance would lead the world to think he possessed. There was something faintly chemical about it. Kind of like an electrical smell, the sort you got from brand new computers. With a slight undertone of oranges. This was not the smell of his clothes or his aftershave or his soap. This was the smell of his blood.

Greg sniffed again. John Watson was with Sherlock. Now John's smell was completely different. He smelt sweeter. Like burnt toffee. With John there was something else though. A musky, animal smell. The smell of the warrior. The smell of carefully coiled danger. John didn't smell of jam and jumpers at all.

He took a deep breath and switched his face into neutral as the door opened.

"LeStrade!"

"Hi Greg!"

"Sherlock, John." Nice and neutral. Don't give anything away. Everyone else was easy to fool. But Sherlock was different. He noticed things.

It was the same old same old really. Sherlock wanted the files. On the two, now three men who had been found drained of blood. He didn't care if they were classified. He wanted the files. Did LeStrade want him on the case or not? etc. etc. John stood at the back trying to pretend he was embarrassed. Looking sympathetically at Greg. Sending silent apologies. And all Greg could sense through the haze of words was the thundering scent of John's excitement because the game was on again.

"Yeah look just go down to Records and get the files." Greg could not breathe for the overwhelming smell of blood in the air. He opened his window, leaning out into the soft glow of the night lit city. Gulping in the fumes from the cars like it was the purest mountain air.

"Are you okay Greg?" John was concerned and right behind him. It would be so easy to turn around and...

"Yeah. Feel a bit sick. Bad sandwich." He felt John's hand pat him on the shoulder. He heard the door open. Sherlock had gone.

"Best go after him. Never know what trouble he'll get into otherwise." John scurried out.

Greg let out the breath he had been holding and looked out of the window once more. A large sleek black car had just pulled up outside the yard. The window wound down a few inches. Greg took another lungful of pollution and suddenly found himself on the floor. Collapsed and gasping like he had been hit by a truck. He sniffed cautiously. The smell still lingered in the air. Stronger than all the scents of the city and all the other people in it. A smell of the richest, darkest chocolate. Not sweet or sickly. Just overwhelmingly sensuous, filling Greg up like a cocaine hit. He couldn't move. He could hardly think.

By the time he was able to regain his feet. The black car had gone.