He was grateful for the soldierly presence of Sir George, still covering the pathways with his Luger. Gently, Joe removed Bonnefoye’s police revolver from its holster and held it at the ready. But he knew the flourish was in vain. The wolf’s killer had made off into the night and was a mile away by now.

The next three days gurgled their way down life’s plughole, barely distinguishable from each other by Joe. A day of sickness and shivering, spent in Bonnefoye’s room in the rue Mouffetard, being Amélie’s replacement son while her own boy was in hospital, passed like a bad dream. He remembered the bowls of chicken soup, the cool hands on his forehead, George’s gruff voice from the doorway: ‘Just back from the hospital. Thought you’d like to hear – the lad’s going to be all right. Blade went in at an angle – the thought is that the attacker was disturbed before he could place his blow more accurately. No vital organs damaged but he lost a lot of blood. He’s on his feet already and clamouring to come home.’

The day after, which must have been a Wednesday, he spent in Fourier’s office making statements, colluding in the fabrication of various pieces of subterfuge. Nodding in agreement as the Commissaire outlined the dashing attack of the Brigade Criminelle officer (trained and directed by Fourier himself) who had gone in against great odds to the rescue (from an attack by a gang of Apaches) of two theatregoers, one a visiting tourist, his companion a Parisian and a distinguished doctor. Sadly, the latter had succumbed to a bullet fired by one of the gang, the former was lucky to survive being hurled into the river by his assailants.

This lively scene was, as they spoke, being worked up by an artist into a cover for Le Petit Journal. Under Fourier’s direction, of course, he reassured them. These creatures were attacking in the very heart of the city now! But thanks to the bravery of the aforementioned police officer, two had been shot dead and would trouble the peace of the city island no more. Patrols on the Square du Vert Galant had been doubled.

‘Seems to be paying off, Fourier,’ said Joe. ‘Though I’d have preferred on the whole not to be summoned down to the river on a wild-goose chase on Monday night.’

‘Ah, yes. Clever devils! Some bugger diverted the two agents on duty down there. And rang directly through to my office, someone knowing my number, leaving a message so official-sounding my sergeant passed it straight on. Moulin. He knows . . . knew the numbers, knew the tones that get attention. Probably expected to catch you while you were still up here sitting in front of me.’

He frowned and fiddled with his pen. ‘I can make this sound convincing enough, Sandilands, for general consumption, I mean, on paper. But I can’t make any sense of it –’ he gestured to his head – ‘up here. What in hell did the stupid bugger think he was doing? Clever man. Reliable. Thorough. My best.’

‘Well placed to cover up a whole crime wave of his own creation?’ Joe suggested. ‘You’ll never know now.’

‘And who’s going to take his place? Good Lord! He’s down there on the slab as we speak! I haven’t been to see him yet . . . I don’t suppose . . .? No?’

‘Who’s going to perform the pathology on the pathologist?’

Fourier burst out laughing. ‘Quis medicabitur ipsum medicum?’ he said, surprisingly. He rose to his feet to show Joe to the door.

‘And I’ll add a second thought on similar lines,’ said Joe cheerfully. ‘Who will police the policeman? I’ll tell you – I will!’

In a moment his foot had come out to trip up the Commissaire and his hand simultaneously pushed him hard between the shoulder blades. Fourier’s head banged against the corner of his desk as he went down and he swore in pain and confusion.

‘Bad luck,’ said Joe. ‘You really ought to have that rug tacked down, Fourier. There was a loose end there somewhere, I think.’

‘Poor old thing! You look jolly peaky still,’ said Heather Watkins, pouring out a cup of tea for Joe at Fauchon’s. ‘But I can’t understand why that woman would do such a thing . . . I mean . . . Well, I can just about see why she would undertake . . . um . . . the profession she undertook . . .’ Heather blushed and hunted about for the milk jug. ‘But how could she have let herself be led into a life of crime by that appalling villain?’

‘I think what she gave me and Bonnefoye was a true bill. Ninety per cent of it. The client who insinuated himself into her establishment probably had some strong hold over her . . . blackmail . . . contrived involvement in one of his early excursions . . . I think he took over her life like a cancer, eating it away. He was using her girls as agents in his schemes. Alice was left only nominally in charge and beginning to realize she was herself replaceable. Good liars tell the truth as far as they possibly can and slip in one big falsehood. She told us truthfully what happened – just gave us the wrong name. Picked an entirely innocent Englishman, knowing he would be able to talk his way out of it – and anyway, Jack Pollock was safe enough behind the walls of the Embassy. The worst thing that could have happened to him in the event of an enquiry was a rap on the knuckles from Her Excellency! And a suspension from opera escort duties. But I believe Alice was truly alarmed by the sadistic nature of the man she found herself tied to. By his complete ruthlessness. It defies explanation, Heather! A professional man, clever, sharp, kind to me when in role. And the other side of him, dark, greedy and murderous.’

‘But why? I know men murder others for the satisfaction, even enjoyment it can bring them.’ She shuddered. ‘But his victims were not known to him in a personal way. Where was the satisfaction in that?’

‘I think he was a bit mad. Working in that place – it would send any man off the rails. And I believe he sensed this was happening to him. He made an effort to keep the stone walls, dripping with sorrow, at bay. It didn’t work. The corpses kept piling up and he kept on slicing and carving and witnessing the very worst man can do to man.’

‘He lost his sensitivity? Like a knife losing its edge?’

‘I think so. He had been a sensitive man. He enjoyed the theatre and the opera – he had posters and programmes all over his room and, Heather, the strangest thing – I’d noticed a photograph on his desk. A pretty dark girl. Her face was vaguely familiar. I checked his room yesterday – I went to return a book he lent me . . .’ Joe’s turn to shudder. ‘I thought it might be his girlfriend. I asked one of the assistants if they knew who she was. They looked a bit shifty, I thought, but one of them spoke up. “Don’t you know her, sir? That’s Gaby Laforêt. The music hall star. Nuts about her, he was! Went to every show. Used to joke that one day when he’d made his fortune he’d . . . Well, we all need our fantasies, working in a dump like this, don’t we?”’

‘But why would he want you dead, Joe? How did you figure in his fantasies?’

‘He overrated my insight, I think. Thought I was nearer to putting it all together than I actually was. After all – I’d confided in him, shown him my cards, in fact. One professional to another. And if you see your opponent is holding a Royal Flush, you assume he’s going to play it. He never suspected that I hadn’t recognized the significance of what I had. So – I had to be eliminated. And – possibly as his grande finale – he couldn’t resist stepping on stage himself for a change. I think no one paid him for that display on the bridge. He treated himself to a private performance. He fancied himself as Louis XIV perhaps, that ardent supporter of the theatre, the Sun King, strolling on in the final scene.’

‘Horrid notion! All the same, it’s doubly depressing to think that a man got his thrills by carrying out another fellow’s fantasies! I expect the money was the more important element, you know. But, there, you survived! And so did Jean-Philippe. That’s all that matters. Is he back at work again?’