A chase through the streets of London, a serial killer hunted down by someone who could have easily been the predator he was chasing, all down to one of the two standing in the hunt. He had done so effortlessly, for it was second nature. The entire Academy knew him as a teacher, doctor, scientist, friend, and demented psychopath, and he was the person selected for this mission.

It was a categorized as a three star mission, mostly because of the high population in the area, and that had the creature eaten close to another fifty souls, it would have been a kishin. That granted, it was still nothing more than another specimen to be collected, and done so flawlessly, by the stitched up meister with literally a screw loose.

He had fulfilled the mission without harm, and had collected another soul for his fleeting research on the way back to the Academy. What was left, however, was a body, one he had forgotten in haste, despite his interest in dissection. He had carelessly left it there to rot while he left with what he had desired.

A text alert rang out from the pocket of a jacket. The owner swiftly retrieved the device and read through: "Found a body. May interest you. At morgue." The owner sighed and quickly texted back to the sender of the message, "Where was the body? SH" He continued his walk back to the flat. How he needed the fresh air. When there aren't any thrilling cases, London could be very boring.

His phone alerted him again. He fished it out of his pocket and read, "Hyde park and cut down the middle. No links yet on who could have done so. Still waiting to ID the body." As pale green eyes finished glancing over the phone's screen, a small smile formed on a pale face graced by curly black bangs. He texted his colleague then spun around and began to hail a cab.

At the morgue

"So, this is the body," said a slightly shorter man with short blond hair and a cream sweater. "Looks like a clean cut- like he was sawed in half." He looked at his much taller friend on the other side of the examination table.

"No. Look at the body. The skin is cut straight and peeled in. It was a giant blade, however…" Pale green eyes glanced here and there over the body. "Molly...?"

He was addressing the brown haired woman standing near the table. She made a small noise in response at her name. "Yes, Sherlock?"

"The name of the victim?"

"No luck ye-"

"Burke Palmer. A serial killer known for snatching up little kids and supposedly poisoning them, at least, and this one has been on Lestrade's radar. A case I've solved for him inadvertently- and the murderer has made it easier to solve." He continued to look over the body as he stated this information. After a few seconds, he breathed in heavily and noticeably.

"What is it," John- the man in the sweater- piped up.

"This case does not concern us, John. I know who this "murderer" is." He fished out his phone and began to text as he was leaving. "Bye, Molly."

"Why did you ask if you already knew?"

Sherlock paused. "To see if you already knew." With that he left.

"Sherlock…," John began as he raised his hand to hail a cab. "Who is the murderer?"

Sherlock glanced at John with a smug look. "A man I've encountered before. His name is Franken Stein, and he is known for his skills in America. He has authorization to hunt down people like Burke Palmer."

John shifted uncomfortably. "So he gets to go around killing whoever he wants as long as it's authorized?" Sherlock nodded.

"He also is a rival. His deduction skills are as advanced as mine. His only weaknesses are insanity and the lure of science-"

"Which is one of your weaknesses, Sherlock."

"Shut up," Sherlock chided.

"So…," John continued as he waited for a cab to stop. "What does he look like?"

"He's the same height as me. He has numerous scars on his body, grey hair, is incredibly fond of his stitch covered lab coat and sweater… and has a screw in his head-"

"I'm sorry- Did you say 'in his head'," John exclaimed. "That's impossible to do without dying," he claimed as he drew pointed glares at Sherlock.

Sherlock only stared back. "You didn't let me finish. He claims it's straight through the skull. I believe that that is entirely untrue. The screw is on a metal piece, like a bolt, that turns. The head and the end are both fastened in the exact same way with a magnet simulating the turning of a real screw. It is either that or a head band. Those seem to be the most plausible."

The cab pulled up and they got in. "So… What kind of rivals are you two? Friends and enemies, or is it more like… Moriarty," John continued.

Sherlock was silent, he was thinking. His lips pursed and then he tilted his head after a moment. "It's better if I explain it to you… "