When I reached the rooms which had been allocated to our Portuguese party, I found Dr Nuñez sitting on a bed in his shirt sleeves, attended by his servant, who was strapping the doctor’s few possessions into a knapsack.

‘Good,’ said Dr Nuñez, with a smile. ‘I was afraid you would not reach us in time.’

‘What has become of the fleet?’ I asked, flinging myself down on one of the other beds and prising off my boots to ease my feet, for I had not taken them off, day or night, since I had left Peniche. My feet stank like rotting meat. Although I had been riding, not walking, the heat had caused my feet to swell and the stiff leather had rubbed blisters on my heels.

‘We have divided our forces.’ His expression was grim and it was clear that he was unhappy with the strategy. ‘Drake has gone in pursuit of that treasure ship, the one which stopped briefly here at Peniche and which is now said to be moored some way up the Tejo, but down river from Lisbon.’

‘But why is the army left behind?’

‘Ruy Lopez and Dom Antonio – and indeed Sir John Norreys himself – think it is best for us to remain on land with the army, so that we may gather up as many of the Dom’s supporters as possible while we march overland to Lisbon. That may be right. It is possible.’

He shrugged. ‘But we would have travelled faster had we gone by ship. And this amateur army has no experience of long marches, certainly not across difficult terrain and in such heat. There are not provisions enough here in Peniche to carry with us for an army. We cannot strip a Portuguese town as we stripped Coruña, so we will have to march some sixty-five miles on empty stomachs and the hope that the peasants can feed us, for we cannot pillage.’

‘Drake has not abandoned us?’ I asked, nervously, for I could never quite trust Drake.

‘He is to meet us at Cascais, on the Tejo,’ Dr Nuñez said. ‘The gold from the treasure ship will help us reprovision there.’

‘And help Drake buy his way back into the Queen’s favour?’ I shook my head. ‘Will he even agree to spend some of the treasure on food for the soldiers?’

His only reply was a grunt.

‘And the army must march all that way in this heat? An untrained English army? They will never survive it.’

‘They must, if ever they wish to see their homes again.’ He got up and struggled into his doublet. ‘At least Norreys does not intend any fighting, at any rate not until we reach Lisbon. It is almost certain Philip will have strengthened the garrison there.’

‘We may not intend to fight,’ I said, ‘but should we encounter any Spanish troops, they may not see it in the same way. We will need to defend ourselves if we are attacked.’

‘That is very true.’ He sounded tired and I realised that this trek of more than sixty miles across the barren Portuguese terrain would be very hard on him – a man as old as my lost grandfather – even if he was on horseback.

‘When do we leave?’ I asked. I realised I would have to stuff my feet back into my boots, if they had not swollen too much. It would be painful.

‘At once. Or as soon as Black Jack Norreys can muster that rabble into some kind of marching order.’

He nodded to his servant to carry away his belongings and turned to me.

‘You had best pack your own knapsack. Did you not leave it here when you rode off? And have you eaten?’ He peered at me. ‘I think your mission has brought you no happiness, but we will not speak of it now. Fetch your knapsack and I will send for some food. You look as if you have not eaten for days.’

I did not admit that he was right, and I knew that somehow I must force down some food or I would be unfit for the journey. When I had collected my few belongings and returned to his room, there was a plate of cold meats and bread waiting for me, and a tankard of thin local wine, which I drank gratefully. I managed to eat the food, washing it down with the wine. Although I could barely taste it, I knew that it would sustain me. With a great deal of difficulty and considerable pain, I managed to force my feet into the unyielding leather of my boots, muttering curses under my breath.

When I was ready, we made our way out to the main courtyard, where I was relieved to learn that there were horses enough for the gentlemen and officers. Since I was exhausted from riding most of the nights as well as the days since leaving the farm, stopping only long enough to rest my gallant horse, I certainly did not think my own legs would have carried me to Lisbon. The common soldiers, however, would have to walk, and at the same time they would have to carry every piece of armour, every item of weaponry, for there were no pack mules or donkeys or carts to be had. All beasts of burden seemed mysteriously to have disappeared, spirited away by the people of Peniche. The soldiers would not, however, be burdened with food. There was none. In the short time Dom Antonio had housed his court at Peniche, our army had stripped the town of everything edible. I understood now why the few people I had seen in the streets had given me a chilly reception. The inhabitants of the town had welcomed us rapturously, indeed with cries of joy, but I am sure they waved us off with even greater rapture.

During the last week while I had made my journey to the solar the weather had turned from merely hot to a blistering heat. A few hours out of Peniche and across the isthmus, our makeshift army quickly began to fail, for they had never yet marched further than the distance between the taverns in Plymouth, Coruña, and Peniche (apart from their scavenging forays into the countryside around Coruña). Some men complained unnecessarily, but within the first few hours there were cases of real need. I found that I was constantly dismounting to tend to one who had fainted with heatstroke or another whose bare feet were lacerated by the stony ground. There were, of course, no spare boots.

‘Cover your head against the sun,’ I would say to one man. ‘Not with your metal helmet. Carry that. Contrive something cool, with a handkerchief.’

However, there were few handkerchiefs amongst the men, who thought them an unnecessary item, fit only for women, when any fool could blow his nose between his finger and thumb, so I showed them how to fastened three or four palm leaves together to make a comical kind of hat, as we had done as children. There was a good deal of ribaldry at this, when they looked at one another, but they soon appreciated the protection from the sun.

To another man, I would say, ‘You are not on ship-board now, to go barefoot. All the way from here to Lisbon the ground will be stony. If you do not have shoes, bind your feet with cloth.’

This presented more of a problem, as did the continued lack of handkerchiefs. Palm leaves could not provide protection for the men’s feet. I wished I had some of that shirt cloth I had used in the citadel of Coruña. In the end, some of the barefoot men resorted to tearing the bottoms off their shirts and binding their feet with these, while others continued to go barefoot, as they had been accustomed to do at home in England. But this was not England.

Late in the afternoon of the first day, I heard a piercing shriek from amongst the plodding soldiers behind me, and looking over my shoulder I could see a knot of men milling about, and all the column of soldiers behind them halted.

‘Doctor!’ The cry was passed along the line. ‘Dr Alvarez, come quick!’

I wheeled my horse about and cantered back to where I could see a man writhing on the path, his face contorted with terror and pain. I slid to the ground, unbuckling my satchel.

‘What is it?’ I demanded. ‘What has happened?’

‘A snake.’ They were all talking at once. ‘A great long snake, six feet at least. He’s bitten on the leg.’

‘Describe the snake,’ I said, as I knelt in the dirt beside the man and turned back his ragged breeches. He was one of those who wore no shoes, and the puncture marks were easy to see, just above the ankle.