Andy McNab - Zero hour

At the checkout I paid with cash and picked up a novelty mosque-shaped dual-zone digital alarm clock that was on special offer. I only needed Dutch time, not Mecca's, but it had a big speaker at the back of the green plastic casing. That meant it would have a decent battery pack to power it.

I shouldered my Bergen and headed deeper into the city centre. I still had a lot of shopping to do. I needed two tool sets, rubber gloves, three thick 500ml drinks glasses, small halogen light bulbs, a couple of metres of tubing and a shedload of aspirin. I needed some bits and pieces from a hardware store too, and a roll of freezer bags – not the zip-tight ones, which still let in air, but ones I could twist shut and seal with a wire twist. They were the only kind that would stop air getting in and causing an explosion before I wanted one.

By the time I got back to Westerstraat my Bergen was filled with nearly everything I was going to need. It wasn't dark enough yet for me to infiltrate the square and do my stuff. I might as well sit, look and listen. I made my way down to the cafe and took a table under the striped canopy. From here I could keep eyes on the target door. When the waitress arrived I ordered a pizza and a big bottle of water.

There was still no sign of life on-target. No light, no movement. There was plenty happening outside it, though. Little kids skipped past, hand in hand with their parents. Some stopped at the cafe for juices and ice creams and all sorts of other stuff that had to be cleaned off their faces with a pressure washer. Then there were shop deliveries, people like me just mincing about, and others engrossed in phone conversations. I sat back and watched, taking in some more of this real-life shit while I waited for my Margherita to make an appearance.

I glanced down at the Bergen. The business end of a red plastic G-clamp poked out of the side pocket. I'd bought it, along with a basket load of other stuff, in Amsterdam's equivalent of a pound shop. I pulled the flap back over it – nothing to do with being covert; everything to do with neatness. Having things sticking out of a Bergen was a big no-no in the army. They could catch or get pulled out, and make all sorts of noise. 'That's what fucking flaps are for,' our instructor had yelled at us zit-covered boy soldiers. 'So fucking flap the fucking flaps over.'

This was the second or third time recently that I'd found myself thinking about all the strange and funny stuff from way back. 'What's in the past belongs in the past' had always been my mantra. What was happening to me? Was this part of the process when you knew you were about to die? Was I going to spend the next two months digging all this stuff up and reap-praising what I'd done and said? Or was the thing in my head growing and pressing the access buttons on Memory Central?

I dug a hand into my jeans and dragged out four Union keys. I'd thrown away the locks themselves, in four separate bins. They weren't the first four I'd picked up. I'd had to hunt for ones that didn't have exaggerated variations in their peaks and valleys. These were as even along the teeth as I could find. I wanted to spend as little time as possible filing them down.

The pizza arrived. I ripped off the crust and rolled up the rest. I'd never seen the point of cutting it up with a knife and fork or one of those little wheels that flick tomato sauce all over your shirt. This method was much more efficient.

As it got darker, I pulled the plastic G-clamp from its pouch and unscrewed the adjuster until it came off completely. I was left with something more like a C than a G. I chucked the bit I didn't need back into the Bergen.

One last check of the target front door and windows. Still no lights. I paid my sixteen-euro bill with a twenty and slung the Bergen over one shoulder. I wandered around the corner, not looking too purposeful, and up between the candle and stationery shops on Noordermarkt.

With the clamp in my hand, I pulled the second Bergen strap over my free shoulder and turned under the arch. This time I went straight up to the gate. You can't hesitate. You have to look like you do this most days; you have a reason to be there, and it's not just to make off with the good burghers' flat-screen TVs. I stood in front of the lock so my body and the Bergen masked my activity, as you would if you were about to insert a key or tap in a few numbers you didn't want anyone else to see.

I focused on the steel plate behind the keypad and worked the open end of the clamp between the wrought ironwork so that the jaws of the C looked set to take a bite out of the panel. The top pad was now poised on the inside of the plate. I scanned the wall to check I hadn't missed a button on my recce, then eased the clamp back towards me so that the pad could make contact with the electronic lock release. There was nothing I could do now but move it back and forth and hope to connect.

I heard footsteps behind me, but passing by on the pavement, not turning in through the archway. Nobody paid me any attention. I manoeuvred the C clamp another five or six times and suddenly heard a gentle buzz. The gate was open. I pushed my way through and closed it behind me.

Sure enough, the archway opened onto the square. I walked with purpose. I was a householder returning home. I always got a bit of a spring in my step after a successful infiltration, but this one felt particularly special. In all probability, I didn't have many more of these to go.

I took cover behind a group of over-sized wheelie bins and got my bearings. The area had been carved up by a good few more low walls and fences since Google Earth had taken its snapshot.

Lights shone at all different levels from the backs of some of the houses. Bodies moved around in one that looked like it had been converted into offices. There were no faces at any of the windows.

I bent down and pulled a pair of dark blue washing-up gloves from a side pocket of the Bergen. I'd ripped them out of their packaging when I'd bought them and thrown it away. I pulled them on and felt around in the Bergen for the mini toolkit. China's finest had set me back ten euros in a hardware store and came neatly packed in a black plastic box.

The set consisted mainly of screwdrivers, but I'd been after the tiniest Leatherman rip-off on the planet. It contained every tool I needed, including a knife and a saw.

'You're only as sharp as your knife.' Another instructor's voice from way back, as clear as a bell.

I shoved all the kit I needed into my jeans pockets, then took off the nylon jacket and left it on top of the Bergen. It could hang out behind the bins for a while instead of rustling on my body.

I jumped up and down to make sure I hadn't left any coins in my pockets, or anything that was going to rattle or fall out. I did one last check that all the other bits and pieces were good and secure in their pockets. I headed for the target, toolbox in my left hand.

I ran through the what-ifs. What if the Passat came in as I was approaching the target? What if another vehicle did? Where would it look natural for me to move to? What if it came in while I was working on the door, and caught me in its headlights?

I had no idea whether any of the doors ahead of me might suddenly fly open. There was a chance the cafe's might. They were bound to have lads coming in and out with deliveries and bin bags. Fuck it, I didn't really care. I was just going for it. If anything, I was upbeat. I was doing what I wanted to be doing. I got a kick out of covert entry and going in and doing things when people didn't know you were there. I always had.

As a kid, I used to break into the local fruit and veg shop and hole up in a corner while I ate their bananas. I wasn't hungry: it was all to do with the fact that I knew I was there and they didn't. When I couldn't sleep, I used to hide under the table in the kitchen. I sat listening as my mum and stepdad smoked themselves to death on Embassy Golds in front of the telly.