Berden and I watched him wearily. None of us would have any sleep that night.

The next morning we received word that Sir Francis was back at Seething Lane and Phelippes was with him. My presence was required. I walked the short distance from Mylles’s house, nearly asleep on my feet, though a fresh wind off the river cleared my head a little. It seemed that, after the thunderstorms, the very hot weather was giving way to something more like the usual English summer. It would be August in three days’ time so of course that would mean constant rain. After all my long hot rides I would be glad of some cooler weather. It was no use mourning for the ruined crops, which were past saving.

Both Phelippes and Sir Francis were in the office.

‘Ah, Kit.’ Phelippes, looking up from his desk, seemed quite glad to see me. ‘We hear you had a busy night.’

‘Busy but unprofitable. Even if Ballard had turned up, Berden could not have arrested him.’

‘I have sent a warrant to Mylles’s house this morning,’ Sir Francis said.

‘Ballard is in Sussex,’ I said. ‘Berden got word late last night.’

They looked at each other.

‘Aye,’ I said. ‘Either planning to escape to France at once, or making sure everything is in place if he needs to leave in a hurry.’

‘Then we had better make sure he is arrested quickly,’ Sir Francis said. ‘However, we have another task for you, Kit. As you made the copy of the original letter from the Scottish queen, written in Curll’s hand, we need you to add something. Thomas could have done it, but the change in the writing might be too obvious.’

He handed me a piece of paper.

‘You see the final form of the wording? We want you to encode it and add it to the end of the letter in Curll’s hand.’

I looked down at the sheet, covered with many crossings-out.

I wd be glad to know the names & qualities of the six gentlemen which are to accomplish the designment, for that it may be I shall be able upon knowledge of the parties to give you some further advice necessary to be followed therein; & as also from time to time particularly how you proceed & as soon as you may for the same purpose who be already & how far every one privy hereunto.

I stared at them. This was what they had hoped the Scots queen would write, but she had not done so. It seemed clumsy to me, surely Mary was far too clever to have written anything so blatant. Even someone as politically naïve as Babington would be able to see that.

They were looking pleased with themselves, clearly thinking it a clever plan to entrap Mary more surely than they had already done. I opened my mouth to speak, then closed it again. It was not for me to question the strategy of these great men. I sat down at my desk and first encoded the passage on a scrap of paper, then carefully copied it in Curll’s hand at the bottom of the forged copy of the Scottish queen’s letter.

As soon as the ink was dry, Arthur Gregory was called in to seal it.

‘You had better not deliver the letter this time, Kit,’ Sir Francis said. ‘Not in that respectable doublet. Babington would smell a rat.’

‘Cassie can take it,’ Phelippes said. ‘We want to deliver it as soon as possible, without any more delay.’

He sent for Cassie, who had also had a sleepless night, and despatched him to Babington’s new lodgings in Bishopsgate Without. Very close to the Theatre, I realised.

For the next few days I worked in Phelippes’s office. Despatches from spies and informants continued to arrive, letters to and from France were intercepted, but Phelippes and I went about the work mechanically, with our minds occupied elsewhere. Both Poley and Ballard reappeared in London, although there was still no sign of Gifford. On several occasions Sir Francis’s men followed Poley and Babington as they strolled together about London, sometimes even managing to catch snatches of their conversation. They could be heard speaking openly of subverting the state and imposing Catholicism on London, but for all the watchers could tell, nothing was said of killing the Queen.

However, the sworn assassin Savage now made his appearance in the city, not apparently taking much trouble to hide the fact. With every day that passed, the tension at Seething Lane became more palpable.

Sir Francis, calling in at Phelippes’s office on Monday the first of August, told us that Poley had reported to him that he had encountered both Savage and Ballard at Babington’s lodgings the previous day and that evening had dined with them all at the Rose Inn by Temple Bar.

‘Babington has been struggling to decipher the Scottish queen’s letter,’ he said, ‘and had to call on his fellow conspirator Chidioke Tycheborne for assistance. Poley was not sure whether the task was completed yet. I think we may have to wait a few more days before he has prepared a reply.’

He walked over to the window and looked out.

‘I am going to Barn Elms for a few days. Poley will report to me there. Babington still believes he can choose between carrying through this infamous plot or turning informer and coming to me. Poley will keep him waiting. I want them all arrested by this Friday.’

‘As soon as one is arrested,’ said Phelippes, ‘the others will take fright.’

‘I know that. In the meantime, I want you to arrange for Babington and Ballard to be held here in my house initially, once they are arrested, so that we can question them privily. Also, have Berden draw up a list of all the principal conspirators. We know most of them, but he may have observed others while he has had them under surveillance.’

Phelippes was busy noting this down, so I took a chance. ‘Sir Francis, you do not look well.’

Indeed his skin was pallid and there were lines of pain deep in his face.

He gave me a bleak smile. ‘Ever the physician, Kit. No, I am not in the best of health. That is why I am going to Barn Elms. I find I can recover my strength more quickly there than in London. However, I must go to Richmond Palace first, to inform the Queen of the state of affairs. Her Majesty is naturally anxious at this difficult juncture.’

More than anxious, I thought. Fearful. As she had every reason to be, with the assassins drawing near to her and still walking free upon the streets of London.

The next day, Babington’s reply to Mary’s letter was due to be ready. Or at least so he had told Cassie when he had delivered the letter with the forged postscript. Cassie returned to Phelippes’s office that afternoon with a grim look on his face.

‘No sign of Babington, sir,’ he said. ‘He seems to have vanished again.’

Phelippes thumped his desk in frustration. ‘This is what he did once before, when Kit went to collect a letter he had promised. Has he gone back to Lichfield? We will have to go after him.’

‘No one at his lodgings knew anything of his whereabouts. Or if they did, they weren’t telling.’

‘God preserve me from amateur conspirators!’ Phelippes spat out, then threw open the door and shouted, ‘Find Berden for me!’

Cassie and I looked at each other. He shrugged and raised his eyebrows, but said nothing.

Phelippes came back to his desk. ‘It’s Tuesday today. Sir Francis wants them all in custody by Friday. How can we accomplish that if they’ve gone off to Lichfield? Is it just Babington, or the others as well? Where is Ballard? Where is Savage? That man Poley, has he played us false again? He is supposed to keep us informed.’

‘Wasn’t he to go to Sir Francis at Barn Elms today?’ I said. ‘Perhaps Babington seized his chance to slip away. Could he suspect Poley?’

How, I wondered, could anyone, even someone as naïve as Babington, ever trust Poley?

When Berden came in, Phelippes gave him his instructions. ‘I want you to check all of Babington’s known lodgings in London, and follow any other leads you may encounter. We must know where he is. We cannot lose him now.’