‘Did you hear them?’ He snapped the words out.

‘They were speaking Dutch, my lord.’

‘Go on.’

‘One man passed a purse of coin to the other, then a small phial of liquid. In his haste he knocked it over and a little spilled on the table. They left soon after, but I wiped up the spill with my handkerchief.’ I took out my handkerchief and handed it to him. ‘It is belladonna. Deadly poison.’

‘What made you think it was intended for me?’ He took the handkerchief and looked at the stain, but did not smell or touch it.

‘The first man was Cornelius Parker, who has dealings with the Spanish and is not trusted by the merchant community here.’ I paused. ‘My lord, you may have realised that Master Berden and I were sent here because of your suspicions of treachery. I believe this is what I have discovered.’

‘You have not said why you think I was to be the victim.’

I looked at the half eaten dishes. ‘You do not feel any ill effects this morning?’

‘Of course not.’ He was becoming angry.

‘My lord, the second man, the man who took the money and the poison, was the man who was here just now, van Leyden.’

His reaction was quite unexpected. He threw back his head and roared with laughter. ‘You are much mistaken, Dr Alvarez. Van Leyden is a loyal friend and servant. I would trust him with my life. I do trust him with my life. Here, take your handkerchief and your tale of poisoning. I think you have been misled by the enthusiasm of youth and your master Walsingham’s belief in traitors hiding behind every wall hanging. Young men must have their adventures to make themselves important.’

He thrust the handkerchief back at me and waved me away. ‘Off with you. I shall finish my meal. And van Leyden will enjoy the joke when he returns.’

I was growing angry myself. ‘I beseech you, my lord, do not speak of it to him.’

‘Away with you,’ he said, turning back to the table.

There was nothing more I could do. I bowed and left the room. Embarrassed and humiliated, I closed the door softly behind me and stood for a moment leaning against it with my eyes shut, trying to control my anger. Leicester had treated me like a stupid child. What difference did my youth make? I had not asked to be sent on this mission by Walsingham and had been reluctant and wary about coming. The increasingly bitter weather was warning enough that I would be needed at the hospital, yet here I was, kicking my heels in an alien town. When I did discover treachery at work, I was laughed at. The shock of finding Hans Viederman’s body rushed over me again and I felt sick. I had seen injuries enough even in my short life, and dead men too, but I had never before seen a murdered man, nor one in such pitiful circumstances. I was sure than Hans’s murder and the whispered conspiracy between Cornelius Parker and van Leyden were somehow connected and boded ill for Leicester, yet he would not listen to my warning.

I opened my eyes to see the Earl’s servant looking at me in concern. I had forgotten that he remained just outside the door, waiting for any summons.

‘Dr Alvarez,’ he said, ‘are you ill?’

I shook my head. ‘No, I thank you.’ I studied his face. He gave every impression of being a loyal servant to his master. I would have to take a chance. ‘But your master may be ill soon.’

‘What do you mean?’ He spoke sharply and took a step nearer to me.

At that moment I became aware of voices coming from above our heads, at the top of the next flight of stairs. One of them was van Leyden’s.

‘I need to speak to you,’ I said urgently. I looked around. ‘Somewhere that we will not be overheard.’

He gave a single brisk nod, then jerked his head toward a door opposite. ‘This way.’

It was a small service room, lined with cupboards and windowless. I wasted no time.

‘What is your name?’

‘Robert Hurst, Doctor.’

‘Well, Robert, I believe your master to be in danger. Last night I saw a man called Cornelius Parker pass a bottle of poison to that man.’ I jerked my chin up. ‘To van Leyden. He also paid him a purse of coin. I also know from an eminent merchant here in the city that Parker has dealings with the Spanish and both men are untrustworthy. Both would do anything for money. Moreover, I believe Parker may be involved in the murder of a former soldier called Hans Viederman.’

I saw that the name meant something to Hurst.

‘Because of Parker’s Spanish connections and van Leyden’s presence in this household, I believe that the poison is intended for the Earl. The Earl himself was suspicious of treachery, that was why Master Berden and I were sent here by Sir Francis Walsingham.’

The most surprising thing about our hasty, whispered conference was that Hurst did not look surprised.

‘I too have worked for Sir Francis in the past,’ he said, causing me to be the one surprised. ‘I have been in the Earl’s employ for five years now, and he trusts me.’

‘He does not trust me,’ I said bitterly. ‘Or at any rate he does not believe me. He laughed at my warning and sent me away like a chastened cur.’

‘His manners,’ Hurst said, ‘tend to be arrogant. All the more so when he suspects he may be in danger. What do you want me to do?’

‘Find the poison if you can, and destroy it. Is it possible for you to search van Leyden’s room? It is in a small phial of green glass, about this big.’ I held my finger and thumb four inches apart. ‘It is stoppered with an ill-fitting cork. That is how I managed to get a sample. It is belladonna.’

‘And if I cannot find it?’

‘Try to persuade the Earl to listen, perhaps he will heed you, even if he turns me away. And watch everything that is prepared for him to eat, especially if van Leyden goes near it. He may have a confederate in the kitchen.’

I handed him my handkerchief.

‘This stain, here, this is what leaked from the bottle. Any apothecary can tell you what it is.’

He nodded. ‘If I fail, and the Earl takes the poison, is there any remedy?’

‘The antidote derives from the calabar bean. If he shows signs of paralysis, staggering, blurred vision, fetch his own physician immediately and warn him that it is belladonna. If the poison is administered, it will be in something with a strong flavour, to disguise the taste. A rich sauce or a thick soup, perhaps.’

‘I will do everything I can.’

We both froze as we heard footsteps cross the floor outside and then the sound of the Earl’s door opening and closing.

‘Van Leyden is back,’ I said.

‘I must go back to my duties,’ Hurst said. ‘But as soon as I have the chance, I will search van Leyden’s room. Where are you lodged in the town?’

‘The Prins Willem.’

‘I know it.’

‘I must go,’ I said. ‘If you can, send me word. When we leave the Low Countries we will be returning to England on a ship called the Silver Swan.’

He nodded and clasped my hand briefly. In that short time he had been transformed from a discreet servant standing in the shadows to a fellow agent of Walsingham’s. I felt a wave of relief that my instincts had proved right. We let ourselves quietly out of the room and went down the stairs as softly as possible. Without further words he saw me out of the front door and closed it behind me.

I walked swiftly away, hoping that neither the Earl nor van Leyden was looking out of the window, wondering why I had taken so long to leave the house. The sun was well up now, but there was no warmth in the air. The snow was as hard frozen as it had been before dawn. My mind churned with possibilities. If Hurst managed to find the poison before van Leyden could use it, he could take it to the Earl and, I hoped, persuade him that what I told him was true. Leicester might still make light of it, assuming the poison was intended for someone other than himself. But even in that case, would he keep van Leyden in his household? A known poisoner?