For the first time ever Athelstan fully agreed with Sir John’s desire for refreshment. They walked quickly through Cheapside down to Fleet Street and into the Saracen’s Head, a cool, dark place off the main thoroughfare. Athelstan was pleased to see that it was empty and insisted that this time he should be host. He ordered the taverner to bring two black-jacks of brimming ale and, since it was Friday, not meat but a dish of lampreys and fresh white bread for himself and Sir John. Cranston took to the food like a duck to water, smacking his lips, draining the black-jack, and shouting for the taverner’s pot boy to come and fill it again. Once the first pangs of hunger had been satisfied, Cranston interrogated the friar.

‘Come, Brother, what do you think? Is there a solution? You are the philosopher, Athelstan, though didn’t one of your famous theologians say “From nothing comes nothing - Nihil ex nihilo!”’

‘There must be an answer,’ Athelstan said, reclining against the cool stone at his back. ‘When I studied Logic, we learnt one central truth. If the problem exists there must be a solution, if there’s no solution there’s no problem. Consequently, if there is a problem there must be a solution.’

Cranston belched and blinked at Athelstan. ‘Where did you learn that?’ he taunted.

‘Logic will resolve this problem,’ Athelstan persisted. ‘That and evidence. The problem, Sir John, is that we have no evidence. We can build no premise without it. We are like two men on the edge of a cliff. A chasm separates us from the other side and now we are looking round for the bridge.’ Athelstan paused before continuing, ‘Our bridge will be evidence, the resolving of Sir Thomas’s riddles about the biblical verses and the shoemaker.’

Cranston shook his head. ‘We should have talked to Allingham.’

‘We did try, Sir John, but he obstinately refused to confide in us though I agree that he knew something. I think he was either going to flee or perhaps blackmail the murderers, without telling us. He made one mistake. He under estimated the sheer malice of his opponents.’

‘What makes you say that?’

Athelstan bit his lip, cradling the black-jack in his hands, enjoying its coolness.