WARNING – IF YOU HAVEN'T READ THE REVIEWS YET AND DON'T WANT TO KNOW THE ENDING, DON'T READ THE REVIEWS. A couple of folks left nice reviews but give the plot away in their comments. For a mystery story – that's a bit of an issue.

Title: Crime is of the Essence
Pairings: Harry/Severus, Past Sherlock/Harry, insinuated Sherlock/John
Rating: M (for a few graphic, but not overly graphic scenes and adult language and concepts)
Word Count: Approx. 42,700 (for the entire story)
Warnings: General man-sex between consensual partners. Mentions of drug use, violence, prostitution, thievery – but only by the bad guys and not described.
Summary: When a man he hasn't seen in almost ten years appears in his home with a man he thought was dead for twenty years, Harry Potter knew his evening had just gotten complicated.

Disclaimer: I do not own Harry Potter or BBC's Sherlock nor do I make money from this. I just like playing with them. Harry Potter is owned by owned by JK Rowling, Scholastic and Warner Brothers in some combination and BBC's Sherlock is owned by, well, BBC.
Author's Note: Done for Snarry Swap 2011. This was a gift vividzephyr whose artwork always inspires me! She asked for a BBC Sherlock/HP crossover. This story is complete in seventeen parts. Named a 'Hot Rec' at "The Daily Snitch" on LJ on January 18, 2011. Squee!

Thanks to my wonderfully patient sister for being my beta and plot advisor when I got stuck. Any remaining mistakes are my own.

Special thanks to NambaWann, lorystar7, carolinelamb and reichan3586 for their help on the German translation in Chapter 13. If I messed it up, it's completely my fault.

Story note: The year is 2018. It's canon until the Epilogue. Harry never married. Ron and Hermione had Rose and Hugo earlier than indicated in the books so that they are older in this story. Rose was born in 2002 and Hugo in 2005. Other minor modifications made without notice probably!

The Sherlock in this story is from BBC's Sherlock which is set in contemporary times. This IS NOT Robert Downey Jr.'s Sherlock nor any traditional versions as portrayed by Jeremy Brett or any other actor. This is Sherlock as portrayed by Benedict Cumberbatch. You do not need to have seen the BBC series to follow this story.

If you are interested in learning more (or seeing pictures from the show), check out their main website: wwwDOTbbcDOTcoDOTuk/programmes/b00t4pgh (note: obviously replace 'DOT' with appropriate url formatting. I have removed it due to FFnet's dislike of urls).

Crime is of the Essence

Prologue – Two Bodies, One Corpse

The bright sunlight streaming through the broken windows was a stark contrast to the grime and filth in the room. Dust, dirt, blood, and several other fluids were spilled across the floor. Most people would not know what those other fluids were, nor would they probably want to know, given the grisly scene. There were obvious signs of a struggle: broken shelves, overturned furniture, and blood lightly splattered across the floor and the wall on the right.

The tall man who had found the scene was most interested in what the majority of observers would pass off as a pool of mud, a thick goopy mud, drying on the floor. It certainly looked like mud except for the bubbles that occasionally burst from it.

Normally, he wouldn't have involved himself without a special request. This time, though, he had noticed the foul stench and broken windows as he walked by the building. But no one else seemed to even notice the store that, as of two days ago, hadn't even been there. He thought the circumstances were unusual enough to warrant a look inside.

Two corpses. That's what he saw. Or rather one corpse, a short man with graying brown hair, and one man with raven-black hair, unconscious, but seemingly dead. If anyone else had happened upon the scene, they would have assumed both men were dead. The man on the right certainly was as his throat had been cut. He turned to look at the other man. A long, sharp surgical knife was placed in his hand. At first glance, the pieces of the broken vase above the dark-haired man's head would indicate that he had been hit by the first man as he defended himself. Or, he thought, a third person wanted the authorities to think that. Clearly, it was to be assumed that the man on the left was the attacker and that his victim managed to kill his killer before dying.

It was convenient. Messy, but convenient. Certainly, the local law enforcement agency would make that their working theory. It was also completely wrong.

He snapped off a couple of pictures before the familiar ringtone sounded. That was the call he'd been waiting for. He answered the line. An image of his partner appeared on the left side of the view screen while his own image appeared on the right as was usual in their video chats.

"John, where are you?" the man asked the caller. He centered the camera facing him so he knew John could see him.

"Hello to you, too, Sherlock. I'm stuck in Piccadilly Circus. I've been held up so I probably won't make it there for some time."

Sherlock turned his blue-grey eyes to the window outside as he heard sirens heading in their direction. "I won't be able to hold the scene much longer." He looked at the clock on the viewscreen and cocked his head to listen to the approaching vehicles. "My guess is they are within 75 seconds of arrival."

"Well, then show me the scene. You might want to record it too," John said. Sherlock coughed in irritation. As if he needed to be reminded of that.

After switching to the camera on the front of the phone, Sherlock did a slow pan around the room. Now he saw John on the left side of the viewscreen and the room on the right side. After a complete 360-degree turn around the room, he walked to the shorter man on the right and zoomed in on the neck wound.

"A long, thin, and very sharp knife made that wound," John concluded. "Zoom out a bit more," he requested.

Sherlock waited for the man to come to the same conclusion he had.

"Hmnn," John mused aloud, "the man was dead or dying before that wound was inflicted. There's not enough blood for it to have been the primary cause of death." He paused a moment and then said, "What's on his arm?" Sherlock zoomed the camera over and gently lifted a sleeve to expose a severe burn mark that covered the length of the man's forearm. "It might help us identify him. I'm assuming you found no identification."

"No. I haven't touched anything. We have 45 seconds."

"Fine. Thermal sensor, please." Sherlock flipped the thermal app on the camera and the image of the body turned into varying shades of reds, yellows and blues. The enlarging blue areas indicated its rapidly cooling state.

"I'll review that later for the time of death. Show me the other body," John asked.

Sherlock took a few steps towards the other man. He was ghastly pale and his almost pitch black eyes were wide open as if in fear, or perhaps, surprise. Again, there was little in the way of blood. As Sherlock held the camera in his left hand, he swiped the muddy substance with the forefinger on his right hand. The somewhat stale odor was all too familiar. One taste confirmed it.

John's voice interrupted Sherlock's thoughts. "I believe that man is still alive. He's not breathing but his body hasn't cooled at all." John sounded surprised. Sherlock had been so absorbed in the fluid he hadn't been looking at the viewscreen. There was a small crunch from the back of the store. Sherlock looked up to see what the noise was but he realized the sirens were just outside and he was out of time.

A sudden thought occurred to him and he lifted the man's left arm. The long black sleeve slid down and a very faded skull and snake tattoo came into view.

"I have to go," Sherlock said and flipped the phone off without so much as a goodbye. He slipped it into his pocket and began rooting around in the other pocket. He heard the vehicle doors slamming as he fumbled for the one thing he'd never thought he would use. As he finally felt the small hexagonal shaped object he was searching for, he placed his other hand on the man and whispered, "Lemon Sherbet." He felt a tug at his navel as the room before him shimmered and disappeared. The last thing he heard was the ringing of a small, high pitched bell indicating someone had opened the door and entered.