"I do not see why he could not have been kept with the other prisoners," Osborne said.

"No, of course you do not," Mayhew replied.

"The Tower's main rooms have held two kings of Scotland and a king of France, our own King Henry VI, Thomas More, and our own good queen. What is so special about this one that he deserves more secure premises than those great personages?" Osborne persisted.

"You have only been assigned to this task for two days," Mayhew replied. "When you have been here as long as I, you will understand."

Crossing the room, Mayhew peered through the bars in the door. As his eyes adjusted to the gloom within, he made out the form of the cell's occupant hunched on a rough wooden bench, the hood of his cloak, as always, pulled over his head so his features were hidden. He was allowed no naked flame for illumination, no drink in a bowl or goblet, only in a bottle, and he was never allowed to leave the secure area of the White Tower where he had been imprisoned for twenty years.

"Still nothing to say?" Mayhew murmured, and then laughed at his own joke. He passed the comment every day, in full knowledge that the prisoner had never been known to speak in all his time in the Tower.

Yet on this occasion the light leaking through the grille revealed a subtle shift in the dark shape, as though the prisoner was listening to what Mayhew said, perhaps even considering a response.

Mayhew's deliberations were interrupted by muffled bangs and clatters in the Mint above their heads, the sound of raised voices, and then a low, chilling cry.

"They are in," he said flatly, turning back to the room.

Osborne had pressed himself against one wall like a hunted animal. The four guards looked to Mayhew hesitantly.

"Help your friends," he said. "Do whatever is in your power to protect this place. Lock the door as you leave. I will bolt it."

Once they had gone, he slammed the bolts into place with a flick of his wrist that showed his disdain for their security.