I was level with the tops of the fourth or fifth tier of buildings now, and could see streetlamps above me, and the occasional sweep of vehicle headlights. I was closing on the upper road.

The balustrade that bordered the steps was lower on this flight. I glanced swiftly over each side of it in case there was an opportunity for an early exit.

There wasn’t.

Just a sheer drop.

Nothing to grab on to.

Nothing to break a fall.

I spotted a point a hundred or so to my left where one corner of the flat roof of a massive yellow block of flats edged close to the parapet. Close enough for me to jump.

I kept low as I approached the road. When I got to it I didn’t bother to stop, listen and look. What was the point? I already knew I had two behind me, and at least one in front.

I bounded out on to the pavement and went immediately left, staying in the crouch, shoulder almost brushing the wall. It gave me good cover from the steps; less good from the streetlights. But why worry about what you can’t change?

Three-quarters of the way to my target, the night was torn apart by the world’s biggest lightning bolt, followed by a crash of thunder loud enough to drown the sound of the moped careering along the tarmac towards me. As soon as the rumble retreated, I heard it big-time. Fuck crouching. I went into Usain Bolt mode, fast and straight. If those lads were carrying, they were going to do more damage to the stonework at this range than they would to me.

Fifteen metres from the corner of the roof, the rain began. Not just a gentle shower, an Italian monsoon. Clear air one second, torrential the next. Moped man mounted the pavement five metres away and rode straight at me. I stood my ground, then jinked right and left and he lost it on the kerb. The engine whined as the tyres lost traction and the bike dropped with a clatter, trapping his left leg beneath it.

His mates appeared at the top of the steps as I took a pace towards him. The climb had slowed them down, but they weren’t going to hang about long enough for me to give this lad a smack and ask him what the fuck they were up to.

They were ten away when I leapt on to the wall.

The distance to my landing zone was further than I’d anticipated. I hate it when that happens. I barely had time to steady myself before pressing the launch button, but I was in the air long enough to wonder what the fuck would happen if I landed on the wet tiles that edged it instead of the flat red asphalt-coated expanse I was aiming for.

I soon found out.

I buried the UZI into the roofing felt and hung on, but the tiles were slippery as shit, and seemed determined to take me down. My arse was hanging in space. I didn’t even want to think about the distance between my flailing legs and the ground. It wasn’t as big a drop as it had been when I was trying not to follow the Nissan off the edge of the mountain, but it was far enough to be a one-way trip.

The only solid thing I might be able to grab hold of was a galvanized-tin chimney cowl with four legs and a lid the shape of a pyramid. But it was a metre out of my reach.

The asphalt coating was like heavy-duty sandpaper. I scrabbled for a grip on it but all I got in return was a set of bleeding fingernails. Apart from the UZI, the only thing keeping me up there was the slight ridge beneath my elbows, where the tiles began, and the friction of my jacket sleeves.

The rain was part curse, part blessing. It was drowning me, but it was also drowning the noise I was making. And though it was making my life difficult from the waist down, the weight of my wet clothes helped to glue my arms and torso to the rooftop.

I balled my hands into fists, wedged my elbows more firmly against the far side of the ridge and levered the top half of my body upwards until I was able to raise my right knee high enough to give it some purchase too. Then I used it to push myself forwards until, at full stretch, I could close my left hand around the nearest leg of the cowl.

I wasn’t dry, but I was almost home.

That was when one of the takeaway pizza team joined me.

He’d misjudged his jump too, but had me to hold on to.

He landed on my arse and right leg and I felt his chin dig into my lower back. He grabbed at my jacket to stop himself sliding back over the edge.

I tightened my grip on the cowl, but it wasn’t designed for this kind of shit, and snapped off its mounting. Which meant that if I didn’t do something fast, we were both fucked.

I managed to bring my right heel up quickly enough to hook it over the ridge as well as my knee. As my body rotated ninety degrees anticlockwise, I lifted my left elbow and drove it back as hard as I could into whatever bit of him was in its arc of fire.

I couldn’t see a fucking thing, but I felt it connect with the side of his head, like a ball hammer on an eggshell.

He didn’t make a sound. He didn’t loosen his hold on my jacket either. He tightened it instead. I could feel him trying to wedge his hands beneath me, trying to grip my thighs in a bear hug.

I slid sideways and back and felt the weight of him and his swinging legs taking me down. I twisted my left shoulder upwards and my head on to the asphalt and managed to bury my fingers in his hair – so it was Mr Moped, not one of his shiny-headed mates – and clamped them strongly enough to be able to bang his face against the tiles.

Another bolt of lightning confirmed that I’d already smashed his cheekbone into the roof of his mouth and taken some of his eye socket with it. He didn’t look happy.

I felt his grip slacken, so I did it again.

And again.

And one more time, for luck.

Then I realized that my hand in his hair was pretty much the only thing that was keeping him there. So I let go, pulled myself up with the UZI and rolled the rest of me into a secure position half a metre from the point he’d just disappeared. I didn’t hear him bounce off anything on the way down. Just the noise of a big sack of shit hitting some very wet ground.

I hauled myself up, dug out the UZI and stayed in the crouch for a moment, listening for any other sign of imminent threat above the driving rain, and looking back at the parapet I’d leapt from. One set of head and shoulders was silhouetted against the streetlamps. The other – along with arms, legs and body – was poised on the top of the wall.

As more lightning split the sky, I saw him measure the gap, then look down and not like what he saw.

I needed to build on that.

They both had blades, but neither was showing anything that might go bang. So I got to my feet and made it clear that I was armed and ready.

A stream of oncoming headlights appeared from further up the road, and seemed to convince the boys that they were on the wrong end of the risk-and-reward spectrum. They pocketed the blades. Going back to pick up those pizzas was suddenly a much safer option.

The one on the wall dropped on to the pavement and his mate picked up the moped and off they went.

I turned and scanned my immediate surroundings. Apart from three other cowls there was a matching skylight, which probably crowned a stairwell. I didn’t bother looking. I could tell from there that it was fixed. It wouldn’t give me access unless I dived through the glass.

To my immediate left was another L-shaped roof, five metres lower than mine, surrounded by a waist-high wall and three horizontal rails, which suggested that the residents came up there on a fairly regular basis, and therefore that the structure like a garden shed at the apex might provide the route in and out.

I got down on my very wet belt buckle and went over the edge feet first, slowing my descent as much as possible with toecaps and sleeves and fingers and my fistful of UZI until I had to let go. I landed more or less upright and legged it round the corner.