Sherlock moved the white chess piece slowly, keeping his eyes on the man across from him.

The man kept his face in the shadows, eyes shining from underneath the hoodie on his head.

"Who are you?" Sherlock finally asked, looking into the eyes.

He tried deducing the man, but everything was just a big question mark.

"Right, you should have a hard time knowing anything about me." He said in a soft voice, moving his black piece and taking a white piece off the chess board.

Sherlock narrowed his eyes. "I came into my flat and found a man in here. You're lucky John and Karrine are out."

"Oh yes, your adoptive daughter and your flatmate. Just a flatmate?" He asked, something edging in his smooth voice.

Sherlock made his next move, taking a black chess piece off.

The man gave a soft laugh.

"Yes, just a flatmate." Sherlock answered slowly.

The man made another move and sat back.

Sherlock cocked an eyebrow. "You could have taken my Knight."

"I like to think long term instead of going straight ahead. That move is like what I'm doing now. This game is that move. I could kill you now, or use this as my…. Preemptive attack."

Sherlock inhaled then exhaled deeply.

"Now, I suggest you play."

John had a sinking feeling in the pit of his stomach.

Karrine was eating across from him, the 8 year old playing with a napkin.

She had sharp blue/grey eyes and wavy black hair.

She looked worried to, but decided to ignore it when Lestrade, off of work, came up to them.

John had a lengthy conversation with him, Karrine interjecting at random times.

Sherlock wasn't winning.

He couldn't stop his hand from shaking and pulse getting quicker.

"If I win…" The man had never elaborated, but the tone of his voice caused Sherlock to know something bad was going to happen if he didn't win.

Sherlock had to many choices to pick from for his next move.

'Preemptive strike.' It didn't make sense.

Not at all.

Just as the man was about to win, he moved his piece at a different place.

Sherlock blinked, and used his next piece to win.

The man got up and Sherlock stood as well.

"Oh Sherlock… Sherlock Holmes…. Never trust the detective in flat 221B…" The man went to the door and left, walking past Mrs. Hudson.

"Who was that?" She asked, eyes wide.

"I have no idea."

"Oh you'll know soon Sherlock. Really soon. Because our chess game isn't done. The chess game isn't anywhere near done."

OK, don't freak out- this is just a one shot. Ok, I know, and if you understood the reference I made in the title, kudos. There will be a sequel, a full fledged story sequel, possibly. Right now I'm working on a BonesLock, but this was nagging at me so... review.