'It's pure speculation,' said Doyle, though there was something about his voice – something quieter and less confident – that struck Anson.

'You instructed me to speculate. You will admit that I have seen more examples of criminal behaviour and criminal purpose than you. I speculate on that basis. You have insisted on the fact that Edalji is of the professional class. How often, you implicitly asked, did the professional classes commit crimes? More often than you would believe, was my answer. However, I would return the question to you in a different form, Sir Arthur. How often do you find happily married men, whose happiness naturally involves regular sexual fulfilment, committing crimes of a violent and perverted nature? Do we believe that Jack the Ripper was a happily married man?

'No, we do not. I would go further. I would suggest that if a normal healthy man is continually deprived of sexual fulfilment, for whatever reason and under whatever circumstances, it may – I only say may, I put it no stronger – it may begin to affect the cast of his mind. I think this is what happened with Edalji. He felt himself in a terrible cage surrounded by iron bars. When would he ever escape? When would he ever achieve any kind of sexual fulfilment? In my view, a continuous period of sexual frustration, year after year after year, can start to turn a man's mind, Doyle. He can end up worshipping strange gods, and performing strange rites.'

There was no reply from his famous guest. Indeed, Doyle seemed quite puce in the face. Perhaps it was the effect of the brandy. Perhaps for all his worldly airs the man was a prude. Or perhaps – and this seemed the most likely – he saw the overwhelming force of the argument ranged against him. In any case, his eyes were trained on the ashtray as he crushed out the perfectly smokeable length of a very decent cigar. Anson waited, but his guest had now transferred his gaze to the fire, unwilling or unable to reply. Well, that seemed to be the end of that. Time to move to more practical matters.

'I trust you sleep soundly tonight, Doyle. But be warned that some believe Green Hall to be haunted.'

'Really,' came the reply. But Anson could tell Doyle's mind was far away.

'There is supposedly a headless horseman. Also the crunching of coach wheels in the gravel of the drive, and yet no coach. Also the ringing of mysterious bells, and yet no bells have ever been found. Tommyrot, of course, sheer tommyrot.' Anson found himself feeling positively blithe. 'But I doubt you are susceptible to phantoms and zombies and poltergeists.'

'The spirits of the dead do not trouble me,' said Doyle in a flat, tired voice. 'Indeed, I welcome them.'

'Breakfast is at eight, if that suits you.'

As Doyle retired in what Anson took to be defeat, the Chief Constable swept the cigar butts into the fire and watched them briefly flare. When he got to bed, Blanche was still awake, rereading Mrs Braddon. In the side dressing room her husband tossed his jacket across the clothes horse and shouted through to her, 'Sherlock Holmes baffled! Scotland Yard solves mystery!'

'George, don't bellow so.'

Captain Anson came tiptoeing through in his braided dressing gown with a vast grin on his face. 'I do not care if the Great Detective is crouching with his ear to the keyhole. I have taught him a thing or two about the real world tonight.'

Blanche Anson had rarely seen her husband so lightheaded, and decided to confiscate the key to the tantalus for the rest of the week.

Arthur

Arthur's rage had been building since the moment the door of Green Hall closed behind him. The first leg of his journey back to Hindhead did little to alleviate it. The Walsall, Cannock amp; Rugeley line of the London amp; North Western Railway amounted to a constant series of provocations: from Stafford, where George was condemned, through Rugeley where he went to school, Hednesford where he supposedly threatened to shoot Sergeant Robinson in the head, Cannock where those fools of magistrates committed him, Wyrley amp; Churchbridge where it all began, then past fields grazed by what could be Blewitt's livestock, via Walsall where the source of the conspiracy must surely be found, to Birmingham where George had been arrested. Each station on the line had its message, and it was the same message, written by Anson: I and my kind own the land around here, and the people, and the justice.

Jean has never seen Arthur in such a temper. It is mid-afternoon, and he bangs the tea service around as he tells his story.

'And do you know what else he said? He dared to assert that it would do my reputation no good if my… my amateur speculations were to be broadcast. I have not been treated with such condescension since I was an impecunious doctor in Southsea attempting to persuade a rich patient that he was entirely healthy when he insisted on being at death's door.'

'And what did you do? In Southsea, I mean.'

'What did I do? I repeated that he was as fit as a fiddle, he replied that he didn't pay a doctor to tell him that, so I told him to find a different specialist who would diagnose whatever ailment he found it convenient to imagine.'

Jean laughs at the scene, her amusement tinged with a little regret that she was not there, could never have been there. The future lies ahead of them, it is true, but suddenly she minds not having had a little of the past as well.

'So what will you do?'

'I know exactly what I shall do. Anson thinks that I have prepared this report with the intention of sending it to the Home Office, where it will gather dust and be slightingly referred to in some internal review which may finally see the light of day when we are all dead. I have no intention of playing that game. I shall publish my findings as widely as it is possible to do. I thought of it on the train. I shall offer my report to the Daily Telegraph, who I daresay will be happy to print it. But I shall do more than that. I shall ask them to head it "No Copyright", so that other papers – and especially the Midland ones – may reproduce it in extenso and free of charge.'

'Wonderful. And so generous.'

'That's by the by. It's a matter of what's most effective. And furthermore, I shall now make Captain Anson's position in the case, his prejudiced involvement from the very beginning, as clear as a bell. If he wants my amateur speculations on his activities, he shall have them. He shall have them in the libel court if he wishes. And he may very well find that his professional future is not as he imagines after I've finished with him.'

'Arthur, if I may…'

'Yes, my dear?'

'It might be advisable not to turn this into a personal vendetta against Captain Anson.'

'I don't see why not. Much of the evil has its origins with him.'

'I mean, Arthur dear, that you must not let Captain Anson distract you from your primary purpose. Because if he did, then Captain Anson would be the first to be contented.'

Arthur looks at her with pride as well as pleasure. Not just a useful suggestion, but a damned intelligent one into the bargain.

'You are quite right. I shall not scourge Anson more than will serve George's interests. But he shall not remain unscourged either. And I shall put him and his entire police force to shame with the second part of my investigation. Things are becoming clearer as to the culprit, and if I can demonstrate that he was under Anson's nose since the beginning of the affair, and that he did nothing about it, what course will be left to him but resignation? I shall have the Staffordshire Constabulary reorganized from end to end by the time I'm finished with this business. Full steam ahead!'

He notices Jean's smile, which seems to him both admiring and indulgent, a powerful combination.