Every day in London, even on just a single, smoky morning, I saw thousands and thousands of people, huffing and puffing in their pinstripe suits, colliding furiously with ambling tourists.

My daily journey involved two different tubes, each woven with an intricate tapestry of people.

One bitterly cold November morning, I stood shivering on the platform, struggling to stay above the surface in the torrent of the treacherous crowd. I stood solidly and gazed ahead, waiting for those three endless minutes to pass until I could be enveloped in the polluted warmth of the juddering Jubilee line.

Finally, the train appeared, packed to the brim full of people. I politely stepped aside, while others, like warriors preparing for battle, got ready to launch themselves onto the carriages.

When the doors slid open, I watched the rows and rows of feet shuffle off, until I saw a pair of black, shining Doc Martens that caught my attention. They certainly won against my own scuffed, worn docs, unrivalled. My eyes travelled up her long slender body, wrapped up warmly in a mustard yellow coat, until I caught sight of her (...my?!) face.

My heart seized in my chest, pulling the reigns down hard on my airways.

The oddest sensation clutched me, as I looked hard at her in disbelief.

It was as though I had caught my reflection in a shop window. She had my pale blue eyes, golden spectacles and a blaze of red hair pulled tight into a braid at the nape of her neck.

I blinked, shook my head slightly and looked again. It was too late. She was lost in the sea of commuters.

For the rest of that journey, I sat staring out of the window, frozen in terror.

Who on earth was she? How could it even be possible?

I felt too astonished to tell a soul - and so my life went on.

Only, now, I was always on the lookout.

Some days, I caught a glimpse of the fierce shade of firey hair racing ahead of me in the crowd. Or sometimes my heart almost shattered in my chest, when staring out of the window, I saw my own eyes staring back at me.

Somehow, a year had passed, and spotting her a few times a week became a strange version of normal.

No one would believe me.

The following November, I stood, as I always did, waiting, for the train home. I had stayed late at the office, and the platform was eerily empty.

Darkness had settled like a thick cloak over the sky, and the cold wind hissed in my frozen ears.

“Emma.” A voice said, in a tone start sounded so startlingly like my own, I span around.

It was me. I mean, it was her.

“It’s my time.” She said as I heard the approaching roar of the train.

“F-for what?”

“To be you.” She smiled - my smile, and gave my trembling body a sudden, violent shove towards the tracks.