Sherlock sat in his chair, fingers steepled under his chin, staring at the fire. John had left hours ago, though as usual Sherlock hadn't even acknowledged his departure. There were more crucial thoughts hurtling round his head. The only thing that gave away his mental unrest was the ever so slight movement of his eyes from side to side.

The cause of this turmoil in his mind was the presence of a certain female residing in the flat below him. He had spent the past few hours in his mind palace attempting to piece together why he was unable to deduce Emily. Sherlock had never taken any length of time to probe his mind palace for anything other than a case above a 6.

He brought up the memory of first encountering Emily and studied it in great detail. The clothes she was wearing, how he had deduced she was a dog walker and even the slight shift in her demeanour when she looked at John. But there was something missing. How could he not see that she was from a loving family, rode horses or had in fact never had a serious boyfriend? (A fact gleaned from eavesdropping at the pub after leaving her that Saturday night.) He was incredibly disturbed at how much thought he had already given this woman so far.

Sherlock had easily deduced from John's return on a certain Friday night, that there had been an attempt at romance between him and Emily. He had also deduced that it had ended with the reassurance from both parties that a friendship was the best path to continue along.

It was noted with curiosity that his pulse had elevated since being in this section of his palace. Why? He knew why, he just didn't want to admit it to himself.

Sighing, Sherlock rose from his seated position and took up his violin. Running the bow across the strings, he picked out the notes and shaped them into an original composition.

He played for several minutes, not realising that Mrs Hudson had entered the room to leave a casserole off.

'That's beautiful dear, is it new?' She spoke softly, not wishing to break the ambience in the room.

Sherlock stopped and turned to her. 'Hmm.' He hummed thoughtfully, his eyes not quite focussing on her.

'I brought you some dinner; I know you're not on a case, so thought you might appreciate a bit of home cooking for once. You and John are always getting those takeaways in, or heading to Angelo's. You need a good nutritious meal every now and then.'

'Ah Mrs Hudson,' Sherlock suddenly seemed to see the extra person in the room, 'Where's John?'

Mrs Hudson smiled, 'He went to meet Emily for a coffee I think, it was a while ago, so I'm sure he'll be home soon.'

At that, they both heard the door downstairs open, the sound of giggling entering with the two people. John could be heard catching his breath and saying goodbye to Emily before she went into her flat as he walked up the stairs. Mrs Hudson passed John in the hall, saying hello and goodbye to him.

'Hi Sherlock.' Not expecting a reply, John sat on the sofa and picked up the paper.

Sherlock watched him for a minute before… 'John, do you have Emily on your facebook?'

John slowly lowered the paper and glared at Sherlock. 'Ok two things, one, you told me facebook was a 'stupid device for simple people to attempt their own deductions of others', and second, please tell me you don't still believe Emily was sent to murder us in our sleep? I think your recent trip to Dorset proved otherwise.'

Sherlock deduced from this that John was still a bit unhappy about his spontaneous trip down south. Waving his hand he said, 'No, I realise that was incorrect, I do however want to conduct an experiment, and for once I believe facebook may be useful. So do you have her as a friend?'

'Yes I do. Now, why?'

'Bring up her profile picture.' Sherlock walked over to John watching him closely.

Tapping on his phone's screen for a few seconds, 'There, now what?'

Sherlock narrowed his eyes as he watched John's face and then grabbed the phone, walking over to the mirror above the fireplace. He looked down at the phone and then up at the mirror. Repeating this several times, John could hear him muttering under his breath.

'…Dilating…elevated…must…other reason.'

'What the hell are you doing?' John all but sighed at him.

'Look at page three of your paper John.' Walking back to the sofa, Sherlock continued to observe John's face closely as he (not entirely unwillingly) turned his gaze to the correct page.

'Why are you staring at me, and will you please answer my questions!'

'Your pupils didn't expand when you were looking at the picture of Emily, however when they were staring at the topless model in the paper, they expanded rapidly. You obviously have no romantic feelings towards Emily at all, however, the same could not be said for…,' he glanced at the paper, 'Sasha, 20 from Southampton.'

'I've told you to stop deducing me. So what was the whole thing with the mirror…oh…Oh!' A look of realisation crossed John's face, 'You! Do you have feelings for Emily?'

'No! It was merely an experiment in my deductive reasoning, I don't believe in sentiment!'

Sherlock turned abruptly, throwing John's phone onto the sofa as he strode out and into his bedroom, forcefully closing his door behind him.

'That doesn't mean sentiment doesn't believe in you.' John spoke quietly before heading towards the delicious smell of casserole in the kitchen.

This chapter comes from a different angle; I think it needed to be covered before the story could continue. It also slightly changes POV part of the way through, I hope that works ok, but I felt it made the chapter a bit more alive (?). Hope you enjoyed, and let me know what you think!