My big worry was the weather. All afternoon the wind had been getting up, and by 8.00 a gale was blowing and driving blasts of rain before it. In a way it was good, as the roar of the storm would cover any small noises we might make; but I also reckoned there’d be hellish turbulence around the edges of those tall buildings.

Everyone was nervous – myself and Whinger no less than the students. As before all operations, our watches seemed to stop or at least slow down to a ridiclous crawl, the hands hardly moving. The snipers came on the air with the occasional bit of news – ‘Green One. Curtains being drawn in Window One . . . Light switched on in Window Two’ – and by 8.05 all four windows had been curtained off. That suited us fine.

As we rehearsed the action sequences again and again, the only person who seemed unmoved was Anna.

It felt very strange to be dressing in Russian kit. Their flak-jackets were heavier and stiffer than ours, and made us pretty clumsy. My helmet fitted my head inside but still felt very big. Realising that it would be difficult to control my explosive charge on its panel while I was crossing on the ladder, I had Nikolai lash it flat to the small of my back, with the handle pointing up behind my head like a short antenna.

When I glanced across at Whinger I was amazed: he looked every inch a member of Omon, with his features hidden under a black rapist’s mask, and only his eyes and mouth showing.

For the tenth time, it seemed, I checked all weapons and magazines.

At last it was time for the off. We went out on foot into the cold, swirling wind through a gate in the railway compound wall, over the wasteland. The odd street lamp was burning in the distance, but the area we crossed was good and dark. With us we had one guy in civilian clothes, to range ahead as a scout and radio back a warning if he met anyone on the stairs. The covert comms system was working well: in my earpiece I could hear the Black team lining itself up in the van they’d arranged for transport, and the occasional remark from a sniper. With the finger and thumb of my right hand I settled the throat mike more comfortably in position.

In the underground car-park of Block B we waited while our scout started climbing. ‘Red and Blue at foot of stairs,’ I reported, and immediately Anna’s voice answered, ‘Vas ponyal. Khorosho.’

A few moments later the scout called to tell us that all was clear as far as floor five, so both teams went scuttling up. After another pause there, we took the next eleven flights straight, and arrived at the top panting.