The woman suddenly gripped my arm. ‘Look!’

Señora Maria had wrested the pike from her dead husband’s hand and climbed on to a pile of rubble which had fallen in from the wall. Across the gap in the defences a young English soldier, an unarmed standard-bearer, was holding aloft the banner of Dom Antonio. Maria Pita lunged at him with the pike, striking him deep in the neck, just where one of the major arteries lies. I caught sight of his startled look before he fell backwards and vanished from sight. The woman had retained her hold on the pike and now raised it in the air.

‘Anyone who has honour, follow me!’ she cried.

After a moment’s shock, the defenders crowded in behind her and I heard another boom from the cannon. As long as the Spanish had cannon balls and gunpowder, there was little chance the English troops could take the citadel.

The other woman had gone from my side. Despite the fire, which continued to burn, it was growing dark. I had seen nothing of Titus. He might be dead or caught up in the fighting, but it was now that I had arranged to meet him. The southeast corner of the town wall was well away from this fighting by the partial breach in the wall. I hoped that meant even the soldiers who had been patrolling beside the postern gates in that far part of the town would have been drawn to the defence of the weakest part of the citadel.

I had had no chance to explore the town in order to find my way to the house I had picked out from the outside of the wall, and it was growing darker every minute. All I had to provide me with any sense of direction was the light given off by the burning buildings, which must lie almost diametrically opposite the position of the house. With this as my sole guide, I set off running through unfamiliar streets, my satchel flapping at my side, passing darkened houses and stumbling over broken cobbles. As I ran, I realised two things. Many of the inhabitants of the upper town were probably still here, but lying low in their unlit houses, for fear of attracting the attention of the attackers. And the streets were so damaged not from cannon fire – our little cannon could never have reached this far. Nay, the best rounded cobbles had been prised up to be shaped into cannon balls. Even as I came to this conclusion I tripped over one of the holes in the street and came down on my knees, my ankle twisted under me.

Cursing, I scrambled to my feet again. I had certainly sprained my ankle, for pain shot up my leg at every steps I took, but I was sure it was not broken. However, it was going to hamper me.

At last I saw the tall house looming ahead against the night sky. I stopped to catch my breath. My heart was pounding and I must wait and think calmly. I had not been able to detect from the outside of the town how the garden was reached from this side. There might be a way into it from the street, or – and this was what I feared – the only entrance might be from the house itself. Now that I was on the far side of the town from the fighting, the fires could only be seen as a distance glow. There was no more than a sliver of moon tonight, and that little was hidden most of the time behind cloud. The house is front of me was dark like all the others, but that did not mean it was unoccupied.

Something moved over to my right. I laid my hand on my small dagger, the only blade I carried, then I risked a whisper.

‘Is that Titus?’

‘Aye.’ A shadow drifted toward me. ‘I do not know who you are.’

The tone was reserved. He had every right to be suspicious. Had he not seen me welcomed by the Spanish garrison and working all day amongst their injured? I wondered whether he carried a sword.

‘I am Christoval Alvarez,’ I said in English. ‘Kit. I work as a code-breaker with Thomas Phelippes.’ My voice was no more than a breath. ‘Sometimes Sir Francis uses me for other missions. As I was coming with Drake’s expedition, he asked me to try to find you and bring you out.’

I racked my brains to find some way of reassuring him. We must not stand here much longer, whispering in the street. How long before my absence from the soldiers’ bedsides was noticed, and someone began to question my all-too-opportune appearance? Then I remembered Titus’s last despatch to Walsingham, which I had been shown.

‘Listen,’ I said, and quoted to him the first few sentences of his despatch, as well as I could remember them.

There was a stirring in the shadows, which I hoped was Titus relaxing.

‘We can easily climb over the outside wall of the garden behind this house,’ I said, trying to ignored the pain in my twisted ankle. ‘But I’m not sure how easy it will be to get into the garden from this side.’

‘There is a gate just behind me here,’ he said, ‘but it is locked.’

I moved closer. I could just make him out now, and behind him an ornate, gilded gate of the kind often seen leading to noblemen’s houses. This was an even grander place than I had imagined, perhaps the home of the town mayor or the governor of the province. The gate was indeed locked, as I quickly ascertained, but the scrolls and bars of the ironwork offered easy footholds for climbing. Without saying anything further to Titus, I seized hold of the gate and began to hoist myself up. Every time I put my weight on my right foot I nearly cried out from the pain, but I clenched my bottom lip between my teeth and continued up until I reached the top. There I paused for a moment, then eased myself down the other side, not daring to jump on to my damaged ankle. While I caught my breath, I could hear Titus climbing over behind me and dropping down from the top of the gate.

I looked around to get my bearings. At the far end, on the left, I had noticed that the wall was stepped down and lower than the rest of its length, but the land beyond fell away in a steep, rocky cliff. If we tried to go that way there was a danger we might fall. We would have to attempt the higher portion. It was lower than the town wall, but still a considerable height. Over to the right there was a shrubbery up against the wall. That might give us some purchase.

I did not speak, but pointed that way and Titus nodded. I realised I could see him now because the cloud had cleared, letting a little fitful moonlight shine down on us. It made it easier for us to see our way, but it also meant anyone looking out from the house would also be able to see us. We began to run softly across the garden, which was laid out in the very formal Spanish style, with a geometric pattern of gravel paths, interspersed with beds of flowers and herbs. We dared not step on the gravel, so we had to make our way awkwardly across the beds, trampling down the plants. It would be all too clear in the morning where we had been.

Halfway across, Titus grabbed my arm and halted me.

‘What’s the matter with you? Are you lame?’

‘Twisted my ankle on the way here.’ I spoke through gritted teeth, for the pain was getting worse and it was a long way back to the ships.

‘Can you climb the wall?’

‘Needs must,’ I said, and set off again.

Somehow we reached the wall at last. I was right. A large bush of yew grew up against the wall, enabling us to reach nearly halfway to the top of the wall by scrambling up its branches. Titus now insisted on going first and I happily gave way. He was not some helpless civilian. As one of Sir Francis’s agents, he would know how to look after himself. When he reached the top of the wall I was already seated in the upper branches of the bush. Without speaking he pointed out hand-holds to me and when I came within reach he grabbed my wrists and hauled me up the last few feet. As we sat on the top of the wall, assessing the far side, a light came on in the house. I tapped his arm. Perhaps we had not been as quiet as we thought, crossing the garden.

‘Jump,’ he said, ‘I’ll break your fall.’ And he jumped down to the ground below the wall.