It was a moist April evening and I’d stepped out of the house without my glasses. Close enough I could recognise the familiar damp pavement and guttered leaves, but in the distance nothing but an endless blur of red, green and orange, removed from reason and set upon some deep black canvas.

The pavement, baked by the afternoon sun, radiated a humid warmth, and as I ambled under fluorescent amber, I basked in its ambience, eyes closed, arms outstretched and palms open, almost buoyed up by it all.

Ah yes, the city had me. The quiet cocoon of my immediate surroundings subtly offset by the faraway cacophony of urban noise – car horns, jet engines, trains; all dampened and comforted by their distance into one simple assurance of life.

I was in central London, walking alone and without purpose, and enjoying every breath of it. It’s odd, really, that cities are not considered natural beauty – quite the opposite, in fact. So often they’re decried for their tax on the environment, sneered at for being pragmatic products of industry, when really it is such efficiency for which nature fundamentally strives.

I challenge anyone to walk along Tower Bridge at four ayem, see the sun spiking through the houses of parliament, with blades of light kicking up off sheer glass walls on either side of the river, and still yearn for some labyrinth of foliage to satisfy them.

People have their ways of levelling themselves. Walking was mine, and it was always at night that I felt most comfortable. This particular night was wonderfully set, and I had started to venture down unknown roads earlier and more swiftly than usual.

It was coming up to midnight when I saw the last road, two blocks behind the nearest major street and more dimly lit than the others. I had no hesitation in continuing down it and why would I? It was beautiful at first. A 1960s brick box gloomed oppressively on my right and a 90s skate park, saturated with graffiti, stuck two fingers up in response on my left.

It was only when I got to the stairs that I stopped. They were fairly innocuous – steel, black paint, but oddly immaculate in condition. They led down and left to a patio of sorts, bathed in some ultraviolet hue, with two long wooden tables and a stack of chairs in the far corner. A slide door to the adjoining building appeared to be open, but without my glasses the glare of the light above it masked everything inside.

No gate, no sign – it was almost inviting. You do not often see such an open off-road in the city, and I would know. Perhaps it was that very abnormality that compelled me to explore it. It wouldn’t take long, I remember thinking to myself. The path is set, the possibilities are limited.

Two stiletto heels marched through my solitude in disgruntled step, with faint mutterings and the rustling of a handbag, falling out of earshot as quickly as they came.

Clock, clock, clock, clock. The noise echoed in my head, forced my feet forward, pushed me down those stairs. The nightly ritual had suddenly evolved into something altogether more exciting. Heart rate up, adrenaline seeping through my body, adventure in my veins and I’d only made it halfway down.

You get past a point of no return when you dare yourself to do something. At the base of the stairs, I’d hit that point. I’d trespassed, I’d explored, I’d done it and I didn’t care, because now there was only one thing I was going to do.

I was close enough to hear the light humming but still I couldn’t see beyond it. At this range the intensity was incredible, the bulb burning itself into my retinas, forcing me to keep moving. Eyes watering, I ducked under the light and through the patio doors.

I was rubbing my eyes for about half a minute, waiting for them to recover from the glare and adjust to the darkness, more or less blinded by the entrance. When I finally looked up to survey my surroundings, he was about two feet away from me.

Clothes dirty and torn, but posture immaculate – he held himself with dignity and control. His sudden appearance, proximity and calm authority struck me dumb. I wanted to apologise, make an excuse, get out of there; but I couldn’t. Truth be told I was terrified. He stood powerfully above me, about an inch taller, silent, blank, unreadable.

I think he let me stew a little. Five, maybe ten seconds. It can feel a hell of a long time in a situation like that. After that came his first and only expression, and then I understood. Cracked slowly upwards through firm lips, he revealed two rows of teeth – a smile – and, spiking down on either side, two fangs, strong and sharp, his hungry eyes focussed on my neck.