I woke suddenly with a pounding heart, unsure for a moment where I was or what had roused me. There was shouting and the clash of sword against sword, then heavy bodies colliding and crashing through the bushes near me. Men were yelling in English and Spanish. All this way from Peniche we had been untroubled by Spanish forces, but it seemed our luck had run out. Clouds which might have given us some protection from the unrelenting sun during the day had built up during the night and obscured all light from moon and stars. Apart from a watch fire some distance away, everything was as black as the inside of a chimney. I could see nothing at all.

I scrambled to my feet, caught up my satchel, and groped about in the dark for my horse. He whickered in alarm and I found him, first by the sound, then by the bulk of thicker darkness. The noises were coming nearer as I tried desperately to free the horse from his hobble. My saddle and bridle were somewhere on the ground, but there was no time to find them. I had ridden bareback often enough in my childhood.

Before I could scramble on to his back, one of our soldiers heaved up out of the darkness. Somewhere another fire or a flare had been lit and silhouetted against its distant glow I could just make out a big fellow I recognised, one of those who had helped the man with snake bite keep on the march, one of Norreys’s professional soldiers from the Low Countries. He peered at me, reaching out to grope for my arm.

‘Dr Alvarez? It is you! Get back here. That’s Spanish soldiers attacking. Our men will see them off, but you’re best out of the way.’

He tugged at my arm. He was breathing heavily. I could smell sweat and fear. His words were confident, but the hand on my arm was shaking.

‘Wait,’ I said, ‘I need my horse’s tack.’

‘This’ll be your b’yer lady saddle, then, that I nearly fell over.’ He gave a brief bark of nervous laughter.

He grabbed something from the ground, just as I caught my feet in the bridle and sprawled flat on my face. Between us we gathered up both saddle and bridle, and I wound my fingers in my horse’s mane to lead him with us. I had been sleeping a little distance away from the main body of our army, for I had an irrational fear that if I slept amongst the men, I might give myself away by talking in my sleep.

The soldier led the way in a long curve round the main part of the camp, where we could see more and more men staggering to their feet, drawing their swords and looking about them in confusion. It was still so dark it was impossible to understand quite what was happening. Torches were flaring here and there amongst the scattered English forces, but it was clear where the attack had been concentrated, on the side where, carelessly, no sentries seemed to have been posted.

My companion pointed this out with contempt.

‘If we had set up camp like this in the Low Countries,’ he said, ‘without proper sentries, I wouldn’t be here today, tramping and starving across this God-forsaken country. We’d all have had our throats cut long ago. Though the Don Juans aren’t making a very good job of it tonight themselves. They should have wiped out more of us by now.’

He spoke in a tone of professional criticism which would have made me laugh at another time.

I was having difficulty keeping up with him and persuading the horse along, for the shouting and the black shapes leaping in the firelight had frightened him. He kept trying to pull away from me.

‘Why had Sir John not seen to it that we were better guarded?’ I was incredulous.

‘Oh, he gave his orders, did the Old Man. But most of this scum pay no heed to orders, unless they have to fight to save their own skins. There aren’t enough of us real soldiers to hold this rabble together. Can’t call it an army. It’s no better than the sweepings off the streets of London.’

‘You speak the truth,’ I said, ‘but what’s to be done?’

I could sense him shrugging. The horse tried again to jerk away and I gripped his mane more firmly. ‘Come along, lad,’ I said soothingly.

‘Just try to survive until we reach Lisbon,’ the soldier said. ‘But what will happen then? Do you think they’ll surrender to us? I don’t. We can’t attack or carry out a siege. We’ve no artillery. We can’t starve them out. We’re more likely to starve ourselves first. They’ll have laid in provisions, and made sure there’s nothing in the country round about for us to eat. There’s more ways than one for a siege to fail.’

‘I don’t know what will happen,’ I said. ‘I really don’t know. But if Drake sails up the Tejo from Cascais, he has cannon on the ships–’ I let my voice trail away. Could we rely on Drake?

He gave a disbelieving snort. It was clear that his opinion of Drake was no better than mine. At home in England, Drake was fêted as a hero for his actions against the Spanish and for the treasures he carried home to the Queen and the others who financed his voyages, but those of us who served with him saw a different side to the man – the ruthless, self-serving pirate, whose first aim in life was to hurt the Spanish as much as he could, and whose second aim was to make himself the richest man in England. Or perhaps that was the first of his goals.

By the time we reached the campfires, the sounds of fighting had dwindled into the distance. Men were milling about in confusion, bumping into each other, tripping over bundles on the ground. I hardly knew whether to laugh or cry.

‘Thank you,’ I said awkwardly to the big soldier. ‘It was good of you to come for me. How did you know where I was?’

‘Saw you go off there. The lads, they’re grateful for what you done for ’em.’ He gave a wicked grin. ‘Wouldn’t rate to lose our doctor, would it? More important that Earls or Kings. That’s what the lads think, anyways.’

He went off, either to join in the fight against the attackers or to help restore some order amongst the disorderly mob. I hobbled my horse again and sat down cross-legged by one of the fires. There would be little more sleep for anyone that night and it was certain my medical skills would be needed. After some time, a jubilant group of soldiers returned, having driven off the attackers with little damage to themselves apart from a few slashes – or so we thought – which I attended to, while Norreys and his senior officers rounded up men to stand sentry, after a thorough tongue-lashing to the ill-disciplined crew who had failed to keep to their duty. In any normal army, those who had deserted their posts would have been executed on the spot, but this was no normal army and our numbers were dwindling dangerously. We could not spare even the men who disobeyed orders. It was a dangerous situation for any army. Once discipline breaks down, an army becomes a violent rabble which is as likely to turn against its officers or each other as readily as against the enemy. I saw that all the victorious men who had chased off the Spaniards came from the experienced Low Countries troop.

I sent for more flares to be set up near me, and by their light I unpacked my satchel and set about seeing to the wounded. There had been no arrows or crossbow bolts, no musket shot, presumably the Spaniards thought they were too risky to use in the dark. They must have feared they would shoot their own men. Some of the sword cuts were superficial, needing no more than salving, but two needed to be stitched, difficult to do by the poor flickering light of the flares. Dr Nuñez joined me, but I saw no sign of Ruy Lopez. Together with the Dom and Norreys he occupied one of the few tents which had been erected, but I could not believe he had slept through the disturbance. Either he was too cowardly to show his face or else he was soothing the nerves of his patron. There was no sign, either, of Essex’s party. I was surprised he had not seized the chance for some heroics, but perhaps he was a heavy sleeper.