He sat down, hailing the landlord, and grandly ordered the best the house could offer. Although thin and scrawny, and at least sixty years of age, Quicksilver ate like a horse and all the time asked me questions. Why had I summoned him? Did I have new medicines? What was he to do?

I told him all about the Great Mouth and the Poppletons. Quicksilver listened intently, then sat back, rocking with laughter. 'Lord above, Shallot, they'll spend all their time on the jakes. And you put aniseed powder in as well? Their skins will be peppered with pustules.' 'How do you know that?' I retorted. 'You are a quack.'

Quicksilver's face suddenly went stern. For a brief moment I saw another man behind those eyes. Do you know, I suddenly realised I knew nothing about Quicksilver: who he really was or where he came from.

'Roger, Roger.' He waggled a finger at me. ‘I have never insulted you. I am not what I appear to be.'

'Most men aren't,' I quipped. I glimpsed the anger in his eyes. 'I am sorry,' I apologised, and gave him my most winning smile. 'I truly am and, when you have finished, most learned of physicians, there will be four, not three coins.'

I must have stirred memories in Quicksilver's soul: he leaned forward and hissed, ‘I have heard of you, Shallot, and your doings at court for the great Wolsey' He gave an icy smile. 'I, too, once worked in the shadows of the great ones: summoned at the dead of night to the Tower; taken to secret rooms to sit by the beds of princes to hear their confessions.' He drew back, as if he had said too much. 'But,' he shrugged, 'that's in the past.'

I never questioned him further. If you live in the shadowy world, as I do, you never ask questions. Take poor Kit Marlowe, killed over a meal. Kit, with his angelic face, mocking mouth and merry eyes. He'd never tell you who he really was. He's twenty years in his grave and already the debate has begun. Was Marlowe a spy? An assassin? Was he an atheist, a Lutheran or a Papist? God knows. The same is true of Will Shakespeare: he's dabbled in enough secrets to provide matter for a thousand plays.