‘The amount of money that passed through the hands of this “relatively minor individual”, as you describe her, bought a great number of guns for the Fenians, Mr Mallon. How long would you have allowed that to continue?’

It was a skilful, tricky question, Swallow knew, put by a senior policeman with a lifetime’s knowledge of his subject.

‘I don’t know, Mr Waters,’ Mallon answered. ‘But I would say that if we had taken the girl out of circulation, it would only be a matter of days before the Fenians would have replaced her. And it might take some time for us to identify her replacement. I’d also say that what is really important is to know the Fenians’ intentions in regard to the weapons they have. And nothing in my intelligence reports suggests that they have any imminent intention of using them.’

Waters nodded thoughtfully. He understood that Mallon had a point, Swallow reckoned.

Balfour raised a hand.

‘There’s a lot of speculation here, and I haven’t all night to sit listening.’

He jabbed a finger towards Mallon.

‘I’m not going to waste time, Mr Mallon, and I’m not at all required to set out any reasons to you to justify my decisions. But I have heard much about you, and I have a high regard for the work you do. I believe it is better that I persuade you to my way of thinking rather than simply issuing a directive.’

He looked to Smith Berry.

‘The assistant under-secretary has taken the matter of Miss Byrne’s or Miss Moyles’s death very seriously. Notwithstanding her unfortunate station in life and her involvement with violent elements, she was entitled to live out her natural span of years, however long or short that might have been. Major Kelly has furnished Mr Smith Berry with a fully convincing account of the circumstances that led to Miss Byrne’s death. And while her demise was unfortunate, I have absolutely no doubt that she was the instrument of her own fate and that no blame whatsoever can attach to Major Kelly.’

Swallow could not contain himself any longer.

‘This girl was attacked savagely. Beaten to death, sir. She didn’t do it to herself.’

‘Do not be impertinent, Inspector,’ Smith Berry snapped. ‘Remember who you are addressing.’

Mallon raised a pacifying hand.

‘You’ll forgive Inspector Swallow’s distress, I know. He has been deeply affected by what happened to his wife when Major Kelly searched his dwelling place. But I would be grateful if you could set out the reasons why Major Kelly is to be exonerated. I cannot see any circumstances in which he can be considered blameless.’