‘Sir, it’s not my function to engage in political issues. But as I understand it, the objective of the government is to bring down Mr Parnell. I feel it incumbent upon me however to tell you that, in my informed opinion, if he falls, the space left vacant will be filled by some very dangerous people.’

‘You’re right on one thing at least, Mr Mallon,’ Smith Berry snapped. ‘It is not your place to question the objectives of Her Majesty’s government. Nor indeed is it mine. But since you have opened up a political discussion, let me offer you another perspective, one that goes beyond a policeman’s short-term objective of keeping law and order.’

He paused to draw breath, as if about to embark on some marathon task or break vital confidences.

‘Mr Mallon, if Parnell has his way, if he succeeds in securing what he calls “Home Rule” for Ireland, the unity of the kingdom will be ended. This great United Kingdom, which has built the most powerful empire that the world has known, will be sundered. If Ireland is lost, what territories will be next? India? Africa? Hong Kong? The Antipodes? A civilisation and an order that spans the globe will be threatened with decline and fall. That, Mr Mallon, is the threat of Parnellism, not whether a few landlords’ houses get burned down in Galway or Roscommon.’

Mallon was silent.

‘That’s a viewpoint, sir,’ he said after a pause. ‘All I can tell you is that if Parnell is displaced, people will die here in Ireland. And preventing that is my responsibility, not saving the empire.’

Smith Berry sat back and extended his arms as if to illustrate a point.

‘And there’s the difference between your task and mine, Detective Chief Superintendent. So, can we go back to the instant matter?’ he asked rhetorically. ‘Lord Salisbury and his colleagues in cabinet, our superiors, know Parnell for a man of double standards and dishonesty, and they are within their rights, indeed they are doing their duty, in exposing it. The details of his private life testify to his dishonesty and double standards. And the records of the men under your command constitute firm evidence of it.’

‘I doubt they do, sir,’ Mallon answered. ‘They may record certain events and details. However, I know Mr Parnell. I know him very well, and I believe him to be a man of honour. But this is beside the point. I do not know where the protection logs are.’

Swallow kept his gaze fixed on the wall behind Smith Berry, trying not to think of the volumes stacked in the space behind the storage cupboard in Harry Lafeyre’s office.

Waters spoke for the first time.

‘As I told you when last we met, I have a great deal of respect for you and your colleagues, Mr Mallon, and for the work you do.’

His tone was conciliatory.