‘I am writing a treatise, have been for years, on the maintenance of the king’s peace in London. The most terrible crime is murder. The belief that a man can kill someone, walk away, and say, “I am not responsible”. I am no theologian, Athelstan, nor a scripture scholar, but the first crime committed after Eden was one of murder: Cain plotting to slay his brother Abel and afterwards claiming he knew nothing about it.’ Cranston grinned. ‘The first great mystery - I mean murder. But nothing like what happened to your brother.’ He turned and spat. ‘That wasn’t murder. That was young dreams and hot blood, minds crammed with stupid stories about Troy and Knights of the Round Table. No, murder is different. And why do men commit murder, Athelstan? For profit? And what will stop men murdering? Hanging, torture?’ He shrugged. ‘Go down to Newgate, as we will do later. The prison is packed with murderers, the gibbets are heavy like apple trees in the autumn, the branches bend with their rotten fruit.’

Cranston moved closer, his face more serious than Athelstan had ever seen it. ‘What will prevent murder, robbery, arson, is when the perpetrator knows, believes, accepts in his heart, that he will be caught and he will be punished. The more vigilant we are, the fewer murders, the fewer deaths. The fewer women slashed from jaw to groin, the fewer men with their throats cut, hanging in a garret or swinging from some beam under a bridge. Your prior knows, Athelstan, that with your guilt and deep sense of justice, you are well suited to such a task.’

He laughed abruptly and went back to this wine cup. ‘If your order produced more men like you, Athelstan, and fewer preachers and theologians, London would be a safer place. That’s the reason I have brought you to this quiet garden, not to some tavern where I would drink myself senseless. No, I want to plot and catch an evil murderer. A man who has slain Thomas Springall and blamed it on poor Brampton, afterwards making his death look like suicide. I believe the same villain executed Vechey and strung his corpse up like carrion under London Bridge.’

Athelstan drank greedily from the water cup, refusing to look at Cranston. He had talked about his brother’s death, and for the first time ever someone had not laid the blame at his door. Athelstan knew it would make no immediate difference but a seed had been planted in his soul. The possibility that he had committed a sin but no murder. That he would atone for it and so the slate would be wiped clean. He put down the cup.

‘You say Springall was murdered by someone else, not Brampton?’ he asked abruptly.