‘I do,’ said Cranston. ‘And so do you. And how can we prove that? The loose thread in this rotten tapestry is Vechey. Now, you may remember when we inspected his corpse, we noticed the water had soaked him up to his knees?’

‘Yes,’ Athelstan nodded.

‘We also know that if Vechey committed suicide he must have done it in the early hours, just before dawn. Correct?’ Again Athelstan nodded.

‘But that is impossible,’ Cranston continued with a self-satisfied smirk. ‘You see, after midnight the Thames runs fast and full. The water rises and it would almost cover the arch. There would be, at the very most, a foot between the surface of the water and the beam Vechey used to hang himself.’ He held up his stubby fingers. ‘First, are we to accept that a man waded through water up to his neck to tie a noose to hang himself? Or that he hanged himself virtually under water? Yet when Vechey’s corpse was found, somehow or other it had dried out except beneath the knees.’

Athelstan grinned. ‘Mirabile dictu, Sir John! Of course the river would be full. Vechey would have had to swim out to hang himself and that is a logical contradiction. So what do you think happened?’

‘Vechey was drugged or knocked on the head, the corpse being strung up for others to find.’

‘But why such contrivance?’

‘I have been wondering about that,’ Cranston replied. ‘Remember, we know very little about the man. Vechey was promiscuous, he liked soft and perfumed flesh but, being a respectable citizen, he would hunt well away from his home in Cheapside. So I think he went down to the stews and bawdy houses along the river. Somehow or other he was trapped, knocked on the head or drugged, and his body taken down to London Bridge. The noose was tied around his neck and strung over the beam. The murderer was very clever, the river bank was deserted. The bridge, as the mannikin told us, was a favourite place for people to commit suicide. The murderer made one mistake. He probably inspected the area when the water had fallen well below the starlings. He forgot that when he came to hang up Vechey’s corpse the river would have risen, covering any suitable platform for a suicide to stand on.’

‘Yet he still went ahead. Why?’

‘Because Vechey was probably dead, strangled before he ever reached that bridge, and what else could the murderer do with the corpse? Throw it in the river still bearing the noose-mark, or cart it round London and risk capture looking for a new gibbet!’

Athelstan smiled. ‘Perfect, Sir John.’

‘And Brampton?’