A fanfiction of the Doctor and Sherlock for one of my friends! Enjoy!

And, many thanks to my beta daleksanddetectives!

Isabella had been the Doctor's companion for several weeks (or had it been just one day?) and was having the time of her life. Seeing her favorite artists and role models and being able to help them in alien situations was a dream come true. Isabella never wanted to leave him. Or so she thought.

o0o

Sherlock had been lying upside down on his chair when a knock was heard in the flat.

"Watson! Door." Sherlock called out, despite John sitting right beside him. John rolled his eyes, but still stood up to open the door.

"Hello?" John greeted, seeing a man and woman holding hands and giggling.

"Oh yes," the man responded, "I'm the Doctor. And this is my very lovely companion Isabella."

"Doctor? Of what?"

"Well, now, it wouldn't be very fun to tell you straight away, would it?" The Doctor smiled and walked past John into the flat. Isabella cautiously stepped inside, giving him a shrug and grin before following the Doctor.

"Ah. So, this is the wonderful Sherlock Holmes, I presume?" asked the Doctor, staring intently at him.

Sherlock didn't even give a passing glance before stating, "No."

The Doctor's eyes widened and he glanced at Isabella before saying, "I didn't even-"

Sherlock quickly sat up before another word was spoken. He was now fully deducing the Doctor, taking mere seconds to read him.

Sherlock looked from the Doctor's face- young had many losses excited easily mischievous- to his clothing- hip mid twenties not police same clothing for days- down to his feet- adventurous dangerous. He saw the look towards Isabella, -obvious attraction not ready for it- and followed the gaze to try and deduce her. Strangely, all Sherlock was able to deduce- intrigued excited attraction (but to whom?) foreign- were simple, elementary things. It was a challenge. But Sherlock was willing to accept.

"But of course you did. It's written all over you." He confirmed it with a wave of his hand.

The Doctor tilted his head and looked extremely puzzled. The sigh inside Sherlock's thoughts was almost audible.

"Your face shows excitement but you still worry because you have lost people- people close to you- to things like this. You wear the same clothes, for you don't have any time to change, jumping from adventure to adventure. You are adventurous, the dirt and scuffs on your shoes say so. You want my help on a case, obviously. I am Sherlock Holmes. Another thing. Your fingers are not callused, leading me to believe you have lied to a certain blogger of mine, for you certainly cannot be a doctor. So, sir, who are you?"

The Doctor blinked in surprise before grinning widely.

"That's brilliant! I knew I came to the right year. Still smart as ever, and as an added bonus, sassy."

The flash of shock appearing on Sherlock's face didn't even compare to the one on John's.

"Sassy?! Sherlock Holmes, that... that arrogant prat? Sassy?! The one who called himself a high-functioning sociopath?! I don't think you understood him correctly." John stuttered, in complete shock that someone who had just met Sherlock would be so unaffected by his deductions, let alone act like, well, that.

Sherlock's face had turned expressionless after the brief misstep. He was now glaring at the Doctor, deducing him using one word that had accidentally slipped when talking. He stared back, knowing Sherlock would soon figure it out.

Sherlock's eyes widened.

"Year... You speak as if you aren't from this time. Which means, however improbable, you can travel in time. And Isabella here, your partner. Not intimate, no not yet, and she," Sherlock turned to her, making her snap to attention, "is why I will be taking your case."