‘This is of no great moment, sirs,’ he said airily. ‘It is a greeting from a friend at Court. He begs me for news of life here in Prague. I thank you for delivering this to me.’
‘Then divulge its contents to us,’ ordered Nicholas.
‘I have just done so.’
‘A letter from a friend does not need to be written in code. Nor does it require secret delivery.’
‘There are some private enquiries in it, which my friend sought to keep between the two of us.’
Nicholas bristled. ‘You forget, Doctor Royden,’ he said, ‘we belong to a theatre company. We stage plays on this theme. The spies in our dramas also write in cipher code and wave their missives over a flame. You thought, for a moment, that the letter was the original, did you not?’
‘No, sir,’ denied the other vehemently. ‘If you wish to know the truth, I was about to burn it. What have I to say about life in Bohemia when I am locked away down here?’
‘Enough of this!’ said Nicholas, grabbing him so tightly by his throat that he could not move. ‘Invisible ink can be made with a preparation of milk and lemon juice. Warm the paper and the secret message appears. That is what you were looking for, but it was not there on the copy.’
‘You are imagining all this,’ said Royden evasively.
‘And am I imagining this,’ demanded Nicholas, pointing to the blood-stained bandage with his other hand. ‘Was it for a letter from your friend that I was attacked and that another man was brutally murdered?’ He pulled him close. ‘Because of these documents, a lady whom I hold dear has been taken as a hostage. You are the only person who can help to rescue her. I will ask you once more, Doctor Royden. Lie to us again and I swear that I will dash your brains out against the wall!’
‘No,’ pleaded the other, recoiling in horror.
‘What is in that letter?’
‘And who sent it?’ hissed Firethorn.
Royden was cornered. There was no means of escape. He had to trust them. He read the letter again, then flicked through the four sheets of parchment with it. He licked his lips.
‘Well?’ said Nicholas. ‘The code used in the first few lines is number substitution. Thirteen occurs three times. What does that number stand for? London? Prague?’
‘Flushing,’ admitted Royden.
‘What of six?’
‘Bohemia.’
‘What about those signs of the zodiac?’ asked Firethorn.
‘They represent people.’
‘Which people?’ pressed Nicholas.
‘You will not know them. They were agents of mine.’
‘What sort of agents?’
‘They gathered intelligence for me.’
‘And where did that intelligence go?’ As Royden hesitated, Nicholas shook him hard. ‘There is a number at the bottom of the page. One hundred and eighty-three. The sender. Who is he, Doctor Royden? Who used us as his unwitting couriers?’
‘It is more than my life is worth to tell you.’
‘Deny us this and you will have no life.’
‘I’ll call for the guard.’
‘You would be dead before he reached you,’ vowed Nicholas, clapping his hand over the prisoner’s mouth. ‘Which is it to be? Do we get the name or do you want your skull cracked open?’
‘From what we hear,’ said Firethorn, reinforcing the threat, ‘we would be doing the Emperor a favour. He would probably knight us for services to Bohemia.’
‘What was the name?’
More hesitation. Nicholas pulled his head forward as if to crack it hard against the wall. Royden’s nerve broke. Unable to speak, his eyes rolled and he nodded vigorously. The book-holder let go of him but stood very close.
‘One hundred and eighty-three,’ he said. ‘Who is he?’
‘Separate the numbers and you may work it out for yourself,’ bleated the other. ‘Eighteen and three. What is the eighteenth letter of the alphabet? What is the third?’
It took them a moment to count through the alphabet.
‘R.C.,’ said Nicholas at length.
‘Roman Catholicism!’ announced Firethorn. ‘That must be it. R.C. Roman Catholicism.’
‘The Popish religion is involved here,’ decided Nicholas, ‘but these letters stand for a name. R.C. Who is high enough to maintain a network of agents on the Continent? Only one man answers to that description. R.C. Robert Cecil.’ He saw the prisoner wince. ‘We know the sender at last. Sir Robert Cecil. Spymaster to the Queen. At least, we have learned that you are working for the right side, Doctor Royden.’
‘But what is the message?’ asked Firethorn.
‘A grim one, sirs,’ said Royden, electing to confide fully in them. ‘My role here is discovered, my reports intercepted. My agents listed here have all been killed. Someone in Prague has betrayed me and sent good men to their death.’
‘Add the name of Adrian Smallwood to that list,’ said Nicholas. ‘He was an innocent victim of all this. But what of the documents we brought?’
‘Details of a new and more complex code,’ explained the other. ‘Sir Robert Cecil has devised it. He instructs me to memorise it and destroy the pages. See here, on this page,’ he said, holding it out to them. ‘That T stands for Tuesday. Sir Robert himself. W is for Wednesday. Balthasar Davey. An agent in Flushing. And so on. I am to gather up all the intelligence I can and send it back to London in the new cipher code.’
‘Who will carry it?’
‘Westfield’s Men.’
‘Not us!’ said Firethorn. ‘We’ve had enough of your cloak-and-dagger work. Deliver it yourself.’
‘That was the intention.’
‘What do you mean?’
‘Master Bracewell was very observant,’ he confessed. ‘I was trying to read the message in invisible ink. There is no need now. I think that I know what it will say.’
‘Well?’
‘Now that I am revealed here, my work is done. Sir Robert is ordering me to quit Prague and return to London with you. Westfield’s Men would be my passport home.’
‘Do not trade on that hope,’ warned Firethorn.
‘How can I? When you leave, I will still be here. Locked up at the discretion of the Emperor. I may never reach London.’ He sagged against the wall. ‘Tell Sir Robert Cecil why.’
‘That lies ahead,’ said Nicholas. ‘Let us look at the immediate situation. Someone has betrayed you. Your agents have been identified and killed. Who was responsible?’
‘I have no idea.’
‘You must have. Name those you suspect.’
‘It could be anyone.’
‘Take us through your day.’
Coaxed by the visitors, Doctor Talbot Royden talked about his work in Prague and the people with whom it had brought him into contact. Several names were mentioned and Firethorn made a mental note of them all. An actor who could learn a twenty-line speech at one reading had no difficulty remembering eleven names in sequence.
Nicholas was satisfied. Much was still obscure but a great deal had been learned. Adrian Smallwood’s death and Anne Hendrik’s abduction had now been put in context. The names in Firethorn’s memory were a starting point. It was time to go.
‘One fear has gone,’ said Royden with a nervous laugh. ‘I was afraid that you had brought word from John Mordrake.’
‘I did,’ said Nicholas, remembering his errand. ‘It is not so much of a message as a gift.’
‘He has no cause to send me a gift. What is it?’
Nicholas took the wooden box from his purse and handed it over. Turning it over in his hands, the prisoner examined it quizzically. He seemed as baffled by it as Nicholas.
‘It lacks a key,’ noted the latter, ‘but Doctor Mordrake said that you would know how to open it.’
Royden held it nearer the flame to study it. There were some Arabic symbols on it in miniature and he had difficulty reading them. The riddle was at last solved. By placing his thumb-nail at one end and pressing hard, he activated a spring. The lid of the box popped open and Royden took something out. Firethorn looked at what he was holding.