He's always found the amorphous nature of his reflection oddly fascinating. Subtle shifts that allow him – at times – to admit the pleasing nature of his face, and at other times means he shaves while wondering how anyone can bear to look at him. Scientifically speaking, he knows that a reflection is nothing more than an image presented on a shiny surface, portraying what is directly in front of it, be it a cloudy sky on a pool of dirty water or a face in a mirror. And yet, he finds himself occasionally captivated by his own reflection in the course of experimenting with a disguise. It's one of those things that he has trouble understanding, much like sentiment.

The first time that he sees his reflection after jumping off the roof of St Bart's is in the men's toilets in the morgue. His eyes burn and throat tightens as he washes away the streaks of fake blood from his face. These reactions are beyond his comprehension, and though it is the same face as it was hours ago, it somehow feels different.

Everything feels different now.

In Madrid he shaves off the curls, dyeing what's left of his hair flaming red. With the green contacts and the newly-acquired tan he hardly recognises himself. Even now, though, he refuses to wear short sleeved shirts, but the loose-fitting blue shirt and jeans that he wears are like nothing that he'd ordinarily deign to pull on. So complete is the transformation that if he were in London and visited any of his usual haunts he would not be recognised.

The idea leaves an odd emptiness in the pit of his stomach.

Verona finds his hair growing out, blonde now, and his eyes only a few shades darker than their natural colour. The small cut on his cheekbone – relic of a fist fight – matches the bruise darkening his stubbled chin. For the first time in a very long time he remembers a day not far from the house of a dominatrix, and the punch to the face that the whole affair brought him. This disguise is undoubtedly better than that one, but the self-praise doesn't help any.

The feeling in the pit of his stomach has grown into a consuming sense of loneliness, though he doesn't realise that that's what this blackness is. Loneliness, after all, implies sentiment.

A year since he's been gone, it's black curls again. Yet, there is a weariness to his eyes which never existed Before, and he's only ever seen in the eyes of others. He slips a cigarette between his lips, regarding the new image almost thoughtfully for a moment before striking a match and lighting it up. Briefly, he wonders what John would say were he to see him now.

It likely wouldn't be anything good.

After the Indian affair with the melting ice-cream, he straightens the curls. It's time consuming, but when he lightens the shade of his hair and adds brown contact lenses, it's worth the time. There's still far too much work to do before he can go home, so he swallows back his thoughts of the comforts of Baker Street and turns his back on reflections. He can't dwell on anything but the work.

It's only a brief glimpse that he catches of himself after Serbia. With his hair a long, tangled mess, cheeks stubbled and face almost-haggard, it's more than enough of a glimpse. He knows that he's not the same man that he was when he left two years ago, but he expects that John will understand just the same.

John always understands, and anyway, Baker Street awaits.