He shook his head. ‘We dare tell nobody. But I checked with the guards who had been in and out of the Queen’s bedchamber during those crucial hours. Nothing unusual: two pages to clean, a maid-in-waiting to prepare the Queen’s bed. And Jane her fool, wandering in to see if the Queen was about. Jane Fool is allowed to go everywhere,’ he added crossly. ‘But she has not the wit to steal an apple.’

‘Finding out who was seen to enter the chamber during those hours is important,’ I said. ‘But someone could have found out about the book earlier, and chosen the hours when her majesty was with the King to make the theft.’

‘How could anyone have known,’ the Queen asked, ‘when I wrote it in secret, told no one, and kept it locked away?’

Lord Parr nodded agreement. ‘We cannot see how this has been done – we have not known what to do. We have felt – paralysed.’

The Queen closed her eyes, clutching the pearl round her neck hard. We all watched her with concern. Finally she unclenched her hand. ‘I am all right.’

‘Are you sure?’ Lord Parr asked.

‘Yes. Yes. But you continue the story, Uncle.’

Lord Parr looked at me. ‘It was then,’ he said, ‘that we heard of the murder by St Paul’s.’

‘Murder?’ I asked sharply.

‘Yes, there is murder in this, too. The book was stolen from the coffer sometime on the evening of the sixth of July. At dusk last Saturday, the tenth, a printer in a small way of business in Bowyer Road, hard by St Paul’s, was murdered in his shop. You know how these little places have multiplied round the cathedral these last few years. Printers, booksellers, often just tiny businesses in ramshackle sheds.’

‘I do, my Lord.’ I knew, too, that many printers and booksellers were radicals, and that several had had their premises raided in recent months.

‘The printer was a man called Armistead Greening,’ Lord Parr continued. ‘His shop was one of those little sheds, with only a single printing press. He had been in trouble before for publishing radical literature; he was investigated in the spring but nothing was found against him. Recently he had been printing schoolbooks. Last Saturday evening he was working in his shop. Several of the local printers were at work nearby; they toil away until the last of the light, to make the most use of their presses. Greening had an apprentice, who left at nine.’

‘How do you know these details?’