Wholock

Police milled around the crime scene. John and Sherlock climbed out of the taxi. The doctor walked under the caution tape and over to the dead body. Sherlock walked around the scene a few times before running into Lestrade.
"What took you so long?" The policeman asked.
"Oh, the usual," Sherlock replied. "What happened?"
"Oh the usual murder." Lestrade replied. "Howevah, he's got no ID of any kind, his clothes are custom, no ones ever seen him before and no one saw him get shot."
"Indeed." The man breathed, his eyes flicking towards a shorter man trying not to be noticed.
"Well, have you got anything?"
Without answering, Sherlock strode to John and the dead body.
"Sherlock, it's the strangest thing," John started. "He has no pulse and his skin is going cold, but those bullets didn't hit any vital organs."
"So what did he die from?" Lestrade asked.
"With the information I have now, no idea." He replied.
Sherlock's eyes flicked back towards the man trying to remain unseen. To his surprise, the man was gone.
"This case has many intricate complications." He mused. "Lestrade, send the body to the morgue. I have some tests I want to run on it."

"What's wrong?" John asked. "You've been quiet all day."
"Hmmm."
"Whatever." He picked up his book. "By the way you're phone is ringing."
"It's Lestrade. Can you get it for me?" Sherlock said absently.
John dropped his book, annoyed.
"Seriously? It's in your pocket!" He said.
The phone stopped ringing. Then John's phone started ringing. He rolled his eyes and answered it.
"Hello?... Yes sorry Greg... Sherlock has it in his pocket... Yes, he wanted me to answer it..."
"Well, tell him to answer his phone next time!... There's been a development in the case..." Lestrade heard a scuffle on the other end.
"What development?" Sherlock's voice came out of the phone.
"Oh now you want to talk to me?" He said. "No... No you listen!... Fine! Alright!... The body's been stolen... Sherlock?... Sherlock?"
The man stood, frozen as his mind raced. John got up and took the phone from Sherlock's motionless hand. Free from the phone, he fell on the couch, deep in thought.
"Sorry about that... Yes you've sent him off on one."
Suddenly, Sherlock jumped up from the couch. He grabbed his coat and ran from the room.
"What's happening?" Lestrade asked, his voice small over the phone.
"Look, I'll call you back." John ended the call. "Sherlock!"

John found his friend back at the crime scene. He stood still with his hands on his temples. The doctor stood off to the side, waiting for him to say something.
"I've missed something, John," he said as he mentally rewound the day.
"What did you miss?"
"I missed... I missed..."
Unknown cause of death; no. Unknown victim; no. The man that was watching...
"I know what I missed." Sherlock said.
"What?" John asked.
"Our witness."

"What do you mean there's a witness?" Lestrade asked.
"I mean there was a man who saw our stolen body get shot, knows why and knows who stole the body." Sherlock replied.
"Oh yeah? And how exactly are we supposed to find him?"
"I have alerted my network," he said, pulling out a paper. "This is a description of our man. I suggest you alert your network. Between us we should find him."
"Alright." Lestrade sighed. "I guess we can work with that."

The next day, John was walking through the park. Enjoying the mild weather, he almost didn't notice Sherlock fall in beside him. So when he spoke, John jumped.
"It's been ages!"
"Sh-! How long have you been there?" John asked.
"I can find anyone! Why can't I find him?" Sherlock mused.
"Good to see you too." He rolled his eyes. "What do you suppose they're looking at?"
John had noticed a gathering crowd on the green. The detective didn't seem to hear him. So, rolling his eyes again, the doctor began walking over to the crowd. There was a burst of flames over the heads of the crowd.
"It's just a fire-dancer," Sherlock said.
"Yes. However, I would enjoy watching him." John replied, pushing through the crowd. "You should come too. It'll be good for you."
The man rolled his eyes, then was compelled foreword as John grabbed his scarf and pulled. Sherlock was about to protest loudly when he saw the fire-dancer. The man in the middle of the clearing looked to be about 5'6. He dark hair and dark, slightly angular eyes. His naked upper body was marred by three long scars from his right shoulder to his left hip.
"What's wrong?" John asked, hearing the sharp intake of breath.
"That's our man." Sherlock replied.
"So, what do we do? Jump him?"
"No. Lets not make a scene," he replied. "We'll wait till after he's done."
The fire-dancer glanced at them as he spit out a massive fireball. The crowd stepped back, shielding themselves from the heat. When the flames faded, they saw that he was gone.
"No!" Sherlock ran to where the man had been.
By the time John had fought through the crowd, he was already running off in the chase. Sherlock followed the signs only he could see like a bloodhound. As his friend caught up with him, he realized the trail had gone cold. John tried to catch his breath as Sherlock shot back past him. Not wanting to do a Scooby chase, John leaned against a tall wood box and watched as his friend ran back and forth.
"He came this way John!" He called. "His trail disappears around here."
Sherlock looked up, seeing John leaning against the tall blue box.
"What are you looking at me for?" John asked.
"What do you suppose that box is?" He asked quietly.
"Dunno. It says police box." John replied. "Is it important?"
"Our mystery witness is in there." Sherlock said, knocking on the door.
"Is he? What if he doesn't come out?"
"I could pick the lock... Actually I don't think I could..." He stood strait. "We need to leave."
"What? Why?" John asked.
"Because our witness will come to us when he's ready." Sherlock replied, walking away.