We went round the block and I signalled to Ronnie to pull over a couple of hundred yards short of the house. She switched off, and for a few moments my ears rang with the sudden quiet. Then she turned to me, and I could see that the red spots were back in her cheeks.

‘What now, boss?’

She really was getting into this.

‘I’ll take a stroll past and see what happens.’

‘Right. What do I do?’

‘Be great if you could stay here,’ I said. Her face fell. ‘In case I need to get out in a hurry,’ I added, and her face picked itself up again. She reached into her handbag and brought out a small brass-coloured canister which she pressed into my hand.

‘What’s this?’ I said.

‘Rape alarm. Press the top.’

‘Ronnie…’

‘Take it. If I hear it, I’ll know you need a lift.’

The street looked as ordinary as it could, given that every single house in it cost upwards of two million pounds. The value of the cars alone, lining both sides of the road, probably exceeded the wealth of many small countries. A dozen Mercedes, a dozen jaguars and Daimlers, five Bentley saloons, a Bentley convertible, three Aston Martins, three Ferraris, a Jensen, a Lamborghini.

And a Ford.

Dark-blue, facing away from me, opposite the house on the other side of the street, which was why I hadn’t noticed it the first time round. Two aerials. Two rear-view mirrors. A dent half-way up the nearside front wing. Sort of dent a large motorcycle might make in a side-to-side collision. One man in the passenger seat.

My first feeling was relief. If they were staking out Sarah’s house, there was a good chance that it was because they didn’t have Sarah, and the house was the next best thing. But then again, they might already have Sarah and had just sent someone along to collect her toothbrush. If she still had any teeth, that is.

No point in worrying about that. I kept walking towards the Ford.

If you’ve ever had any training in military theory, it’s possible that you had to sit through a lecture on a thing called the Boyd Loop. Boyd was a chap who spent a large amount of time studying air-to-air combat during the Korean war, analysing typical ‘event sequences’ - or, in layman’s language, sequences of events - to see why pilot A was able to shoot down pilot B, and how pilot B felt about it afterwards, and which of them had had kedgeree for breakfast. Boyd’s theory was based on the utterly facile observation that when A did something, B reacted, A did something else, B reacted again et cetera, forming a loop of action and reaction. The Boyd Loop. Nice work if you can get it, you may be thinking. But Boyd’s ‘Eureka’ moment, which to this day causes his name to be bandied about military academies the world over, came when he hit upon the notion that if B could do two things in the space of time it normally took him to do one, he would ‘get inside the loop’, and the forces of right would thereby prevail.

Lang’s Theory, which amounts to much the same thing at a fraction of the cost, is that you punch the other chap’s face before he has a chance to get it out of the way.

I came up behind the Ford on the left-hand side, and stopped level with it, looking up at the Woolfs ’ house. The man in the Ford didn’t look at me. Which he would have done if he’d been a civilian, because people do look at people when they’ve got nothing else to do. I bent down and

knocked on his window. He turned and stared at me for a long moment before he wound it down, but I could tell he hadn’t recognised me. He was in his forties and liked his whisky.

‘Are you Roth?’ I snapped, in the best American accent I could manage - which is actually pretty good, though I say so myself.

He shook his head. ‘Roth been here?’ I said.

‘Who the fuck is Roth?’ I’d expected him to be an American, but he sounded extremelyLondon.

‘Shit,’ I said, standing up and looking towards the house. ‘Who are you?’

‘Dalloway,’ I said, frowning. ‘They tell you I was coming?’ Again he shook his head. ‘You been out of the car? Missed the call?’ I was pushing hard, speaking fast and loud, and he was puzzled. But not suspicious. ‘Heard the news? Seen a newspaper, for Christ’s sake? Three dead men, and Lang wasn’t one of them.’ He stared up at me. ‘Shit,’ I said again, in case he hadn’t heard me the first time.

‘What now?’

Cigar for Mr Lang. I had him. I chewed my lip for a while, then decided to take a chance.

‘You here alone?’

He nodded towards the house.

‘ Micky’sinside.’ He glanced at his watch. ‘We change over in ten minutes.’

‘You change over now. I have to get in. Anybody show so far?’

‘Nothing.’

‘Phone?’

‘Once. Girl’s voice, about an hour ago. Asking for Sarah.’

‘Right. Let’s go.’

I was inside his Boyd Loop, that was obvious. Amazing what you can make people do if you get the first note right. He clambered out of the car, eager to show how quickly he could clamber out of cars, and followed at my shoulder as I strode over to the house. I took the keys to my flat out of my pocket and then stopped myself.

‘Have you got a knock?’ I said as we reached the front door.

‘Pardon?’

I rolled my eyes with impatience.

‘A knock. Signal. I don’t want Micky blowing a hole in my chest as we go through the goddamn door.’

‘No, we just… I mean, I just shout " Micky".’

‘Gee, that’s really neat,’ I said. ‘Who worked that one out?’ I laid it on a bit, trying to make him bristle so he’d be all the keener to show how efficient he was. ‘Do it.’

He put his mouth to the letter-box.

‘ Micky,’ he said, and then glanced up, apologetically. ‘It’s me.’

‘Oh, I get it,’ I said. ‘That way he knows it’s you. Cool.’ There was a pause, and then the latch turned and I pushed straight into the house.

I tried not to look at Micky much, so he’d know straightaway he wasn’t the point at issue. But a quick glance told me he was also in his forties, and as thin as a very thin stick. He wore leather backless gloves and a revolver, and probably some clothes as well, but I wasn’t really paying attention to them.

The revolver had a Smith Wesson nickel finish, a short barrel, and an enclosed hammer, making it good for firing from inside a pocket. Probably a Bodyguard Airweight, or something similar. A sneaky kind of a gun. You may ask whether I could name an honest, decent, fair-minded kind of gun, and of course I can’t. All guns throw lead at people with a view to causing harm, but, given that, they tend to have more or less distinct characters. And some are sneakier than others.