It wasn't all that surprising really. She always seemed to leave something behind. Whether of consequence or just boredom, Sherlock had never quite figured out. He'd pinned it down to being a bit of both.
Sherlock glanced down at his hands; cool grey eyes taking in every fine detail the picture being held possessed: the hair the same curly style, though longer than when she'd last been seen. Her frame that of a dancer; petite and graceful, though far from harmless.
He gave a small quirk of the lips as he almost recalled with fondness the time she'd punched him - quite accurately and with considerable force thank you - in the face. The bleeding had been a hindrance in pursuing his latest criminal, but was far less worse an injury than some of the others he had sustained over time.
Though this wasn't what he took the most notice of. The most eye-catching feature was in fact her face; hazel eyes full of energy and hidden intelligence; a coy smile gracing her lips, giving the impression that she knew something he didn't. And at that very moment, she may have. Though Sherlock was not liable to admitting such a thought like that aloud. He did have a reputation to uphold.

It had only taken him mere seconds to notice that something was amiss in the flat.
John, ever faithful John, had meandered towards the kitchen in order to prepare his habitual tea. It was an over indulgence of his, though Sherlock thought it wise not to mention. After all, he always received the offered mug of tea. He seemed to be drinking just as much as John these days.

Whilst John had gone to the kitchen, Sherlock had advanced towards the coffee table in front of his well used sofa.
To the untrained eye, nothing was out of the norm. To Sherlock -who was as far from the norm as possible- everything looked suspicious. And the reason it all looked suspicious, was that it was suspicious.
Papers that had previously not inhabited the coffee table had now found a rather cosy new home. But Sherlock dismissed these; it was what was in fact lying on top of the pages that intrigued him.
A skilled hand reached out and plucked the lone photograph from its roost; eyes analysing and mind deducting at lightning speed. To help further this process, Sherlock had gracefully fallen into a heap on the sofa.

The sound of a whistling kettle could be heard from the kitchen, and various cupboards being opened. Sherlock would have warned John about the pair of arms folded into the fridge -John was searching for milk at this point- but had found that particular activity was further down the 'to do list' than before, and that this picture had taken top priority.

"So what's that then?" a mug appeared magically out of thin air. Of course Sherlock was well aware of the fact that magic didn't exist, that it was all an illusion set up by people with no talents and in desperate need of some sort of financial gain, he had been so focused on the photo in hand that he had actually forgotten about John and the tea. "Mmm?" was the rather eloquent reply.

"Sherlock, what is in your hand?" John was a patient man, but sometimes living with a genius was taxing. The aforementioned genius scrubbed a hand through his curls, never once breaking eye contact with the photo. "John, perhaps you aren't as intelligent as I have previously entertained. I'm sure even Anderson would notice a photograph when he saw one. Although…" Sherlock would have continued to list Anderson's faults, but John wasn't in the mood to hear one of his least favourite people being dissected.

"Alright Sherlock. It's a photo. Who's in it?" the reply was quiet, but intelligible.

"A mystery."

"A mystery?"

"…" Sherlock gifted John with one of the common 'Are you going to repeat things I've already said often? If so, you're an idiot' looks that the majority of the Scotland Yard received. John took a breath to clam himself and tried again. "Does this 'mystery' have a name?"

"Irene Adler. Her name is Irene Adler." Sherlock stared back down at the picture, as if another glance would unlock some secret that had been evading him the last couple times he had looked at it.

John racked his brains in order to come up with another instance he had encountered the name 'Irene Adler'. Try as he might, nothing came forward, and so he was made to feel the idiot again when he asked Sherlock, "Who?"

"So… Irene beat you then?" John was incredulous. Sure he knew there were smart people out there, heck, he was living with one. But to actually hear about his genius flatmate being beaten by another 'arch enemy' of his was just too much. A small chuckle escaped his lips before he managed to catch the murderous look upon Sherlock's. If he had been a cartoon character, thunderclouds and lightning bolts would have been hovering overhead. This lovely mental image didn't help John, and he only chuckled more.

Sherlock flung his arms up and threw himself off the sofa; fully intent on blowing something up in order to get John to stop laughing. "She didn't beat me!"

"What? So it was her womanly wiles then?" John wiped at his eyes. Tears of mirth had appeared.

"You know I don't care for that John. Wiles are for people like Anderson and Donovan." Sherlock shot back.

"So she beat you then. Without using her wiles and, instead, using her brain." John folded his arms across his chest. He knew Sherlock would go off and sulk about this conversation later, but for right now, he just didn't care.

Sherlock's shoulders sagged, though it was only noticeable to the trained eye, and mumbled a response. "Sorry? Didn't quite catch that Sherlock" John itched his nose.

"I said. Perhaps… she beat me a little." Sherlock refused to turn around and meet the Doctor's eyes, but John knew this was only because Sherlock was battling with his pride.

"But that doesn't mean she's going to achieve it again!" Sherlock whipped around and exclaimed with a flamboyant arm gesture. "I'm sure." John gave a smug grin, knowing that it would probably happen again. If the conversation where Sherlock filled him in on all of his other adventures concerning Irene were any indication at all.

Sherlock however, was too busy planning his next plan of action to bother listening to John any longer. He was frantically tapping away on his phone, searching for god knows what. John sensing that Sherlock wouldn't be talking for a while, extracted himself from the sofa, picked up the used mugs, and shuffled towards the kitchen. Being the only responsible adult in the flat, he took it upon himself to ensure that the both of them ate regularly.

A shrill beep from Sherlock's phone sounded and interrupted John's musings on food. "JOHN!" Sherlock dashed into the kitchen, long coat on and John's coat in hand. "We have a case!" He all but manhandled his flatmate into his clothing and then dragged him out the door and down the stairs; after making a quick stop at the table to grab a piece of paper. John had been too busy fixing his clothing to care what Sherlock had grabbed, but was rather unhappy with Lestrade's poor sense of timing. He was hungry.

Sherlock on the other hand, was quite pleased with Lestrade's timing. It meant something exciting was going to happen.

Sherlock kept one hand in his pocket the entire cab ride, fingering the edge of the photograph that was safely concealed from the public eye. The other was occupied by his phone. John was busy trying to decipher where on earth they were and paid no attention to the Consulting Detective.

Which was a shame, because if he had, he might have seen Sherlock withdraw his hand from his pocket, towards the end of the journey, and notice an ink smudge on his finger; withdraw the photo for only a second and then cram it back into its hiding place.

If he had been close enough, he may have been able to see that Sherlock wasn't looking at the photo this time, but the back of it. At the elegant blue writing scrawled across the back.

If he had been fast enough to read it, he would have seen that the writing had read:

'Remember the last time we met? I distinctly remember you being tied to a bed.

I believe the score is 3-0 to me my dear Sherlock.

Must do this again soon,

Irene xoxox'

John however was not able to do any of these things however, and for that, Sherlock was grateful. He hadn't actually noticed the ink until it had appeared on his finger; even when he had been inspecting the photo before in the flat.

Lestrade had said something about a jewellery theft in the text message he had received; he knew Irene was partial to shiny, expensive things. He also knew he had a score to settle. She was too far in front.

Yes, this case was going to hopefully be interesting indeed.