At that moment, the housekeeper came through the door carrying a small tray with the priest’s tea.

‘Pardon me now, Father.’

She laid it on the table and left.

It was as if her intervention had shaken the priest out of a stupor. Now his eyes filled with anger.

‘Mr Swallow, you cannot believe you have authority to question a priest? Do you not realise that I am answerable to canon law, not the criminal law? Your suggestion that I might be guilty of a criminal act is utterly outrageous, but even if it were true you are acting beyond your remit.’

‘I haven’t suggested that you are guilty of anything,’ Swallow said. ‘I said that certain evidence has come to light which requires that I caution you, as I have done. As to your status under canon law and the criminal law, you are answerable to both. Canon law has its own strictures, but I represent the Crown and its laws, including the criminal law. I’m sure you understand that.’

Cavendish laughed lightly.

‘I think the failure of understanding is on your part, Mr Swallow. I am beyond your jurisdiction.’

Swallow reached into his pocket for his handcuffs. He sensed Mossop stiffen with tension beside him as he clanked them noisily between his hands.

‘Now, Father, there’s something that you have to accept, difficult as it may be in your calling. These will fit around a priest’s wrists, if they have to, just as easily as any other man’s. I don’t want matters to go in that direction. So can we get on with our questions? The sooner we can be on our way, the better it will be for everyone.’

Cavendish’s eyes flickered from Swallow’s face to the handcuffs, then back again. There was a long, silent interval before he ceded ground.

‘I have no wish to cause an incident either, Mr Swallow. I will try to answer any reasonable questions you may have. But I warn you, you will hear more about this . . . exceeding of your authority. Do you understand me?’

Swallow ignored both the threat and the question. He put the handcuffs back in his pocket, silently giving thanks that he and Mossop did not have to grapple physically with the young priest.

‘Father Cavendish,’ he began, ‘I have reason to believe that you had an unusual relationship with Alice Flannery, to the degree that you were in the habit of accompanying her home late at night after she had finished work.’

Cavendish shifted in his chair.

‘Don’t you dare to make any suggestion of impropriety, Mr Swallow. I was concerned for her safety. She was . . . vulnerable . . . if you like. I was exercising pastoral care over a young woman I judged to be at risk.’

‘At risk from whom, Father Cavendish?’

‘Well, at general risk. With these London murders, decent women are in great fear.’