Andy McNab - Zero hour

I opened the little tap at the bottom of the container, poured some water into the largest of the cheap aluminium pans and put it on the gas. While I waited for it to come up to the same temperature as a hot bath, I added a little water to the powder in glass number one to make a paste, then added a splash of alcohol. I stirred until it liquefied.

Only now was there time for my stab wounds to get a little TLC. I pulled my jeans down and poured some of the alcohol between the wound and towel padding. It was like my skin was on fire.

I left the mix on the concrete floor and hobbled over to the Passat. Brogues wasn't in complete rigor mortis yet. Everything but his eyelids was still soft and pliable. The process normally starts two to three hours after death and it can take maybe another four for all the muscles and organs to stiffen. It was cold in the loading bay, which would speed things up. The eyelids are among the first bits to go rigid, along with the jaw and neck. His eyes were no longer closed; he stared dully out of the boot. That was why the poor used to place coins over them to keep them closed.

His skin was already pale. The blood had settled in the parts of the body closest to the ground and had drained into the larger veins. The back of his head didn't look as beaten about as I'd thought it would. I pulled off his handmade brown suede shoes. I needed the matching socks.

I tried to sit down while I shoved a sock over glass number two, but my buttock wasn't at all keen. I had to stand and lean down instead. I poured the aspirin mix into the sock sieve. Cloudy liquid trickled through. After a while I removed the sock and wrung out the dregs. I didn't want the rubbish that was left – that was just the bulking agent. What I needed was in the glass – or, rather, what was going to be left after I'd evaporated the water and alcohol out of the liquid. But that was still a few steps away.

Glass number two went into the simmering water. It was going to take about twenty minutes for the alcohol and moisture to evaporate and leave a residue of white powder.

The next stage was to add the acid. Concentrated sulphuric was a lot harder to come by, these days, because of anti-terrorist legislation. Unless you're an industrial chemist, buying it arouses suspicion. My original plan had been to drain some of the Panda's battery acid, but the Passat was a bonus. Or so I thought. There was more of it, but it was a fucker to get out. Everything under the bonnet was covered and sealed to make it look all nice and Gucci. Nobody serviced these things any more: they just plugged them into diagnostic machines.

I poured out a third of the contents of each cell into one of the smaller cooking pots. Even depleted, the battery would still work. The battery acid had to be boiled until all the white fumes had disappeared. It had to be seriously concentrated.

The method for making picric acid hadn't changed for years. It was discovered in the late 1700s, and initially used as a yellow dye for silk and wool. Its explosive potential was discovered a hundred years later. The problem was, this stuff was so strong it attacked common metals like lead and copper to create even more dangerous salts, which were sensitive to shock. During the Boer War, the artillery boys threw shells into their guns and blew themselves up. There were some massive explosions in factories and ammunition ships. Tin and aluminium were the only metals picric acid didn't corrode. Millions of tons of the stuff were used in bombs and grenades in the First World War. They were all coated with tin to prevent the acid contaminating the metallic shell. Even so, munitions factory workers were nicknamed canaries because of the way it stained their skin.

Then they discovered that picric acid was only a nightmare in powder form. Even these days, if the powder is stored in a glass or plastic bottle, you have to take enormous care not to trap grains of it in the threads of the bottle and cap. It's so volatile that just unscrewing the top will make it detonate.

I was going to miss the kick of being able to get shit like this together and see the results. The payoff would be sitting on the flight to Russia with Anna on one side and somebody tapping away on his laptop on the other and me thinking, When you watch the news today you'll see what I've been up to.

I could see the white powder starting to settle in glass number two as the water simmered gently around it. I took the pan off the cooker and replaced it with the one holding the battery acid. It wasn't long before white haze was rising and wafting round the lock-up. Once it had stopped, I poured some of the concentrated acid into glass number three. Then, using the plastic knife, I slowly shifted the white powder out of glass number two and added it to the other so it became a white liquid.

All I had to do now was add a bit of potassium, before placing glass number three in the water and letting that boil down until the mixture turned a yellow-orange colour.

The final stage would be to filter it through a second sock placed over glass number four. But this time it wouldn't be the liquid I was after. I wanted what stayed behind in the sock. The yellow and – thankfully – wet lumps that remained were what this process was all about. Once dried, they would turn into one big fuck-off unstable explosive that could be detonated very easily by heat or an electric charge. For now, however, it would be stored wet in a double layer of freezer bags, twisted, folded over and fastened with the wire retainer to keep the air out and the acid wet. I would keep filling the bags until I had enough.

Friday, 19 March 07.20 hrs I'd fallen asleep in Brogues's camel-hair coat, lying on the footwell carpets from the Passat. I'd spread them out on the floor alongside my four bags of explosive.

I forced myself up off the concrete. There was plenty more to do.

The first thing was to empty the water container to prepare it for its next payload. I opened the tap and let it run out on the floor. Next I got hold of the set of blister-packed halogen bulbs. The plastic packaging was so rigid I had to use the Chinese Leatherman to make any headway.

These bulbs were just what I needed. They were small, they banged out a huge amount of instant heat, and for their size they were more robust than normal bulbs, which were increasingly hard to find anyway because of EU green legislation. These ones would probably be banned as well when the law makers found out they could be used as detonators.

I pulled one out. It was about the size of the tip of my little finger. It had two loops of metal at the bottom for terminals.

The mosque digital alarm clock was next out of Santa's Bergen. I shoved in four AA batteries, then yanked out the leads that connected the power source to the speaker at the back. I twisted the bare wires around each of the bulb loops and set the clock to 08.00. Then I set the alarm for 08.01. Bang on time, instead of me getting the muezzin's wail, the bulb lit up. After three seconds it was hot to the touch – not enough to detonate anything, but that didn't matter for now. I was going to do something else to the bulb to bring it up to speed. I turned off the alarm clock to save the batteries and put it down.

The twenty-litre container had emptied. I picked it up, together with the length of clear plastic tubing I'd bought from a shop that sold tropical fish, and headed for the Passat.

I opened the fuel cap and shoved the tube down into the tank. With the empty container by my feet, I put the other end of the tube to my lips and sucked. My lungs filled with petrol fumes but I kept going. A few seconds later, the tube darkened. As soon as the fuel had risen to within an inch or two of the tip I slid my thumb over it and took it out of my mouth. I pointed it down into the container, pulled my thumb away and the fuel flowed.