I hit the ground running.

I’d only needed a moment – the unlocked door, the guard distracted by some disturbance further up the corridor.

I didn’t hesitate. In a moment I was outside, blinking into the low yellow sun, keen cold air in my face. Unbelievably, just to my right, a discarded filing cabinet – one broken drawer handing open – leant against the outer wall.

I didn’t hang around to wonder at my good fortune. I scrambled on top of the cabinet, hands scrabbling for purchase on damp metal. My foot slipped and knee flared with pain as it struck a sharp corner. But then I was up, and stretching to grasp the top of the wall. One huge pull, brief frantic battle against rough bricks, praying I didn’t lose my grip. Then up, over …

It looked a long way down the other side of the wall, but there were scrubby bushes at the bottom. Would it be enough to break my fall? Whatever, I couldn’t wait. I steadied myself, prayed a quick prayer to whoever might be listening, and jumped.

Landed. A stab of pain in one ankle (and the knee still hurt), a cut on my hand – but I didn’t stop to inspect the damage. If I was hurt badly, I wouldn’t be able to run, would I?

But I did. I hit the ground running.

I was committed now – there was no way to explain this, to be found on the other side of the wall. And every second counted. It could have been no more than fifteen or twenty seconds since I’d taken my chance with the open door, but already my absence might have been noticed, even with the anarchy inside. I was known as a quiet inmate who gave no trouble, and so I’d be looked for only after my more troublesome peers had been dealt with. That might only buy me – what? – thirty more seconds? A minute? Two? But that might just be enough.

I have never run so fast as I hurtled across the open ground between the wall and the trees ahead. My feet hammering the hard earth, pain jarring my joints; lungs on fire, heart hammering in my ears, eyes stinging with sweat.

And with every excruciating second: waiting for the siren to sound behind me, for the shouts. For the barking of foaming dogs straining on leashes, the pounding of other feet in pursuit.

I half sprinted, half stumbled into the line of trees and was swallowed in green shadows. I paused then, sinking down with my back against a towering oak, hidden from view. And listened. And heard nothing, apart from my own convulsing gasps.

Heard nothing from behind, but instead my head was all cacophony. What had I done? What had I done? What was I going to do now?

I knew only one thing: I had to keep moving, to put as much distance between me and the place I had run from as possible, before that inevitable siren sounded (I could hardly believe it hadn’t already). Before my throbbing ankle and sore knee seized up completely.

And so I half run, half hobbled onwards, deeper into the woods. Tripping once on a tree root, then again on a trailing bramble. But always picked myself up and barreled on. On, on: that was all I kept repeating in my head.

Until I emerged, sweating and shaking, onto a sunlit street. I slowed down then, not wanting to draw too much attention to myself. Before long I found a long, old coat, stained and damp, bundled behind a bench – the abandoned property of some street-dweller no doubt. Its musty, mildewy odour was not pleasant, but it hid my clothing. I turned my face away from every passing car, willing myself to be invisible.

As I walked into the suburbs of the nearest town, I saw her. I blinked – no? Yes! On her bicycle, hair streaming behind her. She saw me, gave a cry of delight. Swerved over, jumped off. Her arms around me. Wrinkling her nose at the smell of my coat, but laughing. Her cool hand in mine. How much I had to say, I hardly knew where to start. But we had time now, together. Free.

I opened my eyes reluctantly, raucous shouting echoing down the corridor outside. Clanging of metal on metal. Yawned, and studied the shadows on the ceiling. That was a good daydream. One of the better ones. Impossible of course. A conveniently open door? And just one door? A filing cabinet against a conveniently low wall? And only one wall, with no barbed wire on top?

And what were the chances of running into her, that quickly? To say nothing of the miniscule probability of me remaining free as we walked off together into that fantasy sunset. No, if that was a movie script, it would have been laughed out of the pitch meeting.

But no one else had to believe it. Only I had to, and then only for a few blissful minutes. If I let myself dwell on her, on what I had lost, for too long … but until then, I could be free in my mind at least. I could go anywhere when I closed my eyes. And maybe, just maybe every day I endured in here was one day closer to something better.

Once, I had glimpsed, through barred windows, a man who looked like me, walking along the street next to a girl who looked like her. Heads bent over identical phones, hunched silently against the cold rain. Close but not together, united only in tragic ignorance of what they had. I screamed in my head: you fool, you stupid fool.

And I wondered, as I sometimes do: why is freedom wasted on the free?