Captured

I must've been out for hours, days even; I don't know where I am or what happened, all I know is that I need to get out soon and then run the hell away from here.

"Hello"? I call blindly as I recover consciousness. The fogs of lost time fade before my eyes as I spottily look into the bleak darkness. "Is anybody there? Hello"? Distantly I can here the tedious drip dropping of water which rings wildly in my ears and echoes within the blankness of my subconscious thought. Where the hell am I?
I go to stretch my arms but find them bound tightly behind my back. As I wriggle my fingers I feel the blood rush swiftly to them, thus causing a tight tingling at my finger tips which leaves them feeling tender and numb.  I fight against the ropes which burn my wrists.  After a few futile attempts at escape, I realise that all I've managed to do is cause deep searing wounds, which then cause a sharp pain every time I flinch.  As I inhale through my teeth,  a hiss escapes as I wince with the inscrutable pain. Tears well up in my eyes and I blink them away. The only think I am currently in possession of is my dignity, so I may as well keep that intact; I must stay strong. "Oh my God someone please help me"! My knuckles clash painfully with the metal box which incases me, well at least I believe I'm in a box. The smooth metal which occasionally makes contact with my skin on all four sides is cold to the touch.

In the distance a nearly inaudible squeak of a hinge can be heard, followed by a click. Echoing towards me come striding footsteps which stay constant but increase in volume. I catch my breath and listen intently, yes, I think I can here the sound of someone breathing.

I wriggle against my confinements and throw my weight against the durable steel which confines me, it doesn't even bend under the pressure. As the footsteps grow ever more audible, panic rises within me. It could be someone who'd help me but then why are they alone. I doubt I'm in a public place for the echoes imply a large enclosed space, such as a large building or warehouse.
The steps eventually stop outside of whatever I am enclosed in. I hear the echoes stop and then the familiar scrape of a shoe scuffing on a concrete floor to change direction. There is a clang of keys and then the creaking and grinding of a lock being unclasped. The container I'm in shakes mechanically causing me to go rigid with fear. My breath comes in quick rhythm, a constant cycle of in and exhales which finally reach a crescendo. The lock turns and the door opens. A dim bulb shines rust-coloured light from a distance beyond  the door and leaves me temporarily blind. A man grunts with satisfaction and then a hand grabs my bound wrists.