'What did you do to get posted here?' asked one.

Evidently, this thankless duty was assigned as a punishment, not an honour. 'I misheard an order,' I said.

'Lots of soldiers have been hard of hearing today,' he laughed. We said little more to one another. There was nothing to do but watch the lines of men as they jostled to get on to the bridge, giving them the occasional shove when they got too much out of shape. I inspected every face that went past, as well as trying to keep an eye on the mounted men that crossed by the other bridge, but there was no sign of Iuda. What I would do if I saw him, I was not sure. To kill him there and then – one French soldier killing another, apparently unprovoked – would mean almost certain and instant execution for me. Despite the fact that I had voluntarily walked into the midst of a desperate enemy, I was in no mood for suicide. Iuda's death was now a secondary issue to me. What I needed from him was certainty. If I was lucky, I would have the opportunity to see him die afterwards, but now I had to know, one way or the other, what had happened between him and Domnikiia.

I could think of no other way to determine it. I could ask Domnikiia herself, but I would not believe her answer; at least not if she denied it. I would believe her only if the answer she gave was the one I did not want to hear. I could find the man she claimed she had been with that night, but he would, for the sake of his reputation, instantly deny ever having heard of her. Iuda was the only other person who knew for sure. He had already told me that it had been Domnikiia, but he had previously allowed me to believe that it hadn't. I would go through hell – and this frozen exodus seemed to me a pretty close thing – to get a definitive answer from him.

That afternoon, I was bestowed with an unexpected privilege, if that is the correct word for it. For the first and only time in my life, I saw Bonaparte himself in the flesh. Accompanied by the once mighty Imperial Guard, he made his way across the larger bridge to the west bank of the river. He was not the man I had imagined him to be. My image of him was formed from engravings and paintings and stoked by his reputation. It was no surprise if today he was not at his best. He was both older and fatter than any picture I had seen of him. His nose was not hooked, as is often portrayed, but of normal size and with a slight, hardly noticeable bend. His hair was not black, but of a dark reddish-blond. I wondered if the images I had seen of his empress, Marie-Louise, were as inaccurate and whether Domnikiia in fact looked anything like her. Though he tried to ride upright and erect, he had a tendency to slouch in his saddle. His mouth held the grimace of a man in pain. Despite all this, his blue eyes still burnt with a fury. Was this the look of the intense desire for conquest that had brought the whole of Europe under his heel? Or was it the glazed shield of defiance of a man despairing at his humiliation?

For those tired remnants of the Grande Armée, it was still the former. A cheer – with which I instinctively joined in – went up as he passed by, even from those men still in the water, working to ensure that the bridges would hold up long enough to get not only their emperor, but every one of his subjects across to safety. For at least an hour after his crossing, there remained a stir in the atmosphere, an increase in conversation and a general feeling that all would survive and make it back home. Looking out across the mass of those still waiting to cross, however, I could see that the enthusiasm was not felt universally. But around me, the feelings were genuine. Only when he was long gone did some sense of reality return to the men with whom I stood.

'I'm surprised they're still bothering, now he's across,' said one, his eyes flicking back and forth between the men who continued unendingly to file past.

'He'll get us out,' said another.

'Why so sure?'

'Because it's another two hundred leagues to Warsaw. He needs us till then.'

'But do we need him?'

'Could you have got the bridges built?'

That night, to my astonishment, the horde that had been filing in unbroken procession across the bridges petered away to nothing. Tens of thousands still remained to cross, but they sat around huge campfires, roasting the flesh of fallen horses and waiting to recommence the crossing in the morning. With hindsight of the number that failed to make it across before the full Russian forces fell upon us, this was a ridiculous waste of time, but no one gave the order, and so no one crossed.

The quiet darkness would be a perfect opportunity for Iuda to slip over the bridge, avoiding the crowds, and I tried to stay awake and so prevent him, but I could not. Had Iuda come by that night, I would not have noticed. Had he seen me, he could have killed me with ease. But he did not come that night.

I woke at about seven. I could hear the sound of artillery, closer than it had been the night before, but I do not think it was that which woke me. I looked and saw a solitary figure crossing the river via the smaller bridge. There was no question of it being Iuda, although his hat and clothing completely obscured his face; he was far too short. He was dressed in a bearskin – at least, that was the outermost layer – with a hole cut in it from which his head protruded. It was practical, if inelegant. I could only guess that he was that rarity of a French soldier who had the independence of mind to cross the river when the opportunity was there. I felt sure he would be one of the few that made it safely back to France.

Soon the sun rose, and the crossing of the Berezina resumed en masse. The indolence of the previous night now forced an additional urgency during the day. All had heard rumours that the Russian forces were closing in on our side of the river, and we began to hear to the north and east the sound of battle which was not so far distant when it began, and grew ever nearer as the day went on.

Later in the day, when the first Russian cannonballs began to fall on the riverbank itself, any remaining vestige of orderliness evaporated. The crowds around the entrances to the bridges became more disorderly, and those who failed to angle themselves on to the bridges began to be pushed into the water by the crowds behind them.

Laden with too many horses and too many carts, the larger bridge began to sag in the middle and soon, with a wrenching and creaking of splintering wood, a section of it crumpled into the river. Horses, wagons and men were swept downstream. Those on what remained of the bridge on the far side dashed to safety with an alacrity they had not shown when it was intact. The crowds on the bank at first did not realize what had happened and continued to push on to what they thought was a bridge but was now a jetty. Dozens were forced off the bridge's broken end and into the river – soldiers becoming sailors as they were obliged to walk the plank into which the bridge had been transformed by its collapse – before any order was restored. As people realized what had happened, there was a rush to the other bridge, where I was standing watch. By now all the other guards had abandoned their post, either voluntarily or simply swept away by the crowd. A French marshal – I think it was Lefebvre – stood at the end of the bridge and tried to restore order, but the crowd ignored him and in the end he was forced to cross with them, rather than resist and be trampled underfoot. I retreated behind one of the piles that supported the bridge, my feet lapped by the river water as it scurried over the ice, and continued my vigil.

As darkness fell there was still no sign of Iuda. I had always known it was a long shot, but now I realized that, unclear as I was what I would do if I found him, I had no idea whatsoever of what to do if I didn't. If the evacuation continued then I would soon be swept across the bridge with the rest of the troops. Somehow, I would have to get away from them. Doing so on this side of the Berezina would be preferable, but I could foresee the possibility of having to creep back across this bridge or another, somewhere else along the river, to return to Russian lines.