‘That’s right. And then I ran basic background checks on Endiom, on Julian and his wife, and everything came up clean. So it’s cool. He’s fine.’

Saul laughs, rapping his knuckles against the wall. In an attempt to move off the subject, I say that it’s his round and he goes to the bar, buys two more cañas, coming back with his mood completely unchanged.

‘So you ran background checks?’

‘That’s right.’

‘And what came up about Sofía?’

‘Sofía?’

‘Yes, the woman he was with. Julian’s wife. Didn’t you catch her name?’

The sarcasm has deepened. There is mischief in his eyes.

‘I hardly know her.’

‘She’s good looking,’ he says.

‘Do you think?’

‘Don’t you?’

‘It’s not that. I’ve just never thought of her that way. She’s not my type.’

‘Not your type.’ A small silence, then Saul says, ‘What age would you say she was? Early thirties?’

‘Probably. Yes.’

‘Very smart? Very sexy?’ It takes me a moment to realize that he is quoting from our earlier conversation. He stares directly into my eyes. ‘You’re fucking her, aren’t you?’

Yet again he has seen right through me. I use the noise of the bar and the low light to try to disguise my reaction.

‘Don’t be ridiculous.’

He ignores this.

‘Does Julian know?’

‘What are you talking about? I met her for the second time tonight.’

‘Oh come on, mate. It’s me.’ Why am I bothering to lie, and to Saul of all people? What possible harm could come from him knowing? ‘Your little exchange in Spanish? That was about Pedro Almodóvar? It wasn’t about both of you saying how much you missed each other and how awkward things were getting with me and Julian hanging around?’

‘Of course not. Where’s this coming from?’

I seem to possess a default personality set to perfidy and misinformation. Not for one moment has it occurred to me to tell Saul the truth, but my relationship with Sofía is one of the few things out here that gives me any pleasure, and I don’t want him trampling on it with his decency and his common sense.

‘You remember Mr Wayne,’ he says, ‘Our Spanish teacher at school – the one with the BO problem?’

‘I think so…’

‘Well, it turns out he was pretty good. I understood what you were saying…’

‘And what was that?’ I raise my voice above the music. ‘Seriously, Saul, you can’t have understood. I was apologizing to Julian’s wife because you’d turned into Barry Norman. It was getting embarrassing. Just because you thought she was fit doesn’t mean I’m fucking her. Christ, the way your mind works…’

‘Fine,’ he says, ‘fine,’ waving his hand through the air, and for a moment it appears that he might have believed me. I would actually relish the opportunity to talk to Saul about Sofía, but I do not want him to judge me. The adultery is my sole concession to the darker side of my nature and I want to show him that I have changed.

‘Look, what about a different bar?’ I suggest.

‘No, I’m tired.’

‘But it’s only one o’clock.’

‘One o’clock is late in London.’ He looks deflated. ‘I was up early. Let’s call it a night.’

‘You sure?’

‘I’m sure.’ He has withdrawn into disappointment. ‘There’s always tomorrow.’

We finish our drinks, with scarcely another word spoken, and head out onto the street. I feel as if I am in the company of a favourite schoolmaster who has discovered that I have deceived him. We are waiting in his study, the clock ticking by, just killing time until Milius can find it in himself to come clean. But it is too late. The lie has been told. I have to stick to my tale or risk humiliation. So nothing has really changed in six years. It’s pitiful.

Perhaps as a consequence of this argument – and several others that occur over the course of the weekend – I allow Saul to stay in the flat while I am working in San Sebastián. He was clearly not ready to go to Cádiz, and I did not have the heart, or the nerve, to ask him to move into a hotel. He played so cleverly on my sense of guilt on Friday night, and ridiculed my paranoid behaviour to such an extent, that forcing him to leave was out of the question. He would, in all probability, have simply hopped on the next plane back to London, never to be seen again. Besides, I told myself – unable to sleep on Sunday night – what harm could come from allowing my best friend to stay in my house? What was Saul going to do? Bug the place?

Nevertheless, before leaving for the coast I take several precautions. Details of the safe house in Alcalá de los Gazules are removed and placed in my PO Box at the post office in Moncloa, ditto coded reminders of email addresses, computer passwords and bank accounts. I have €14,500 in cash concealed behind the fridge in a plastic container, which I place in a black bin liner to stow beneath the spare wheel of the Audi. Safes are pointless; most can be cracked in the time it takes to boil a kettle. It is also necessary to disable my desktop computer by removing the hard drive and telling Saul that the system is clogged by a virus. Everything is password protected, but an expert could hoover up most of the information on the system using a modified PDA. If Saul wants to check his email, he can dial up from his own laptop using a mobile phone or, better still, go to an internet café down the road.

I wake at seven on the Tuesday morning and open the windows of the sitting room, letting the flat air for five minutes as coffee bubbles on the stove. Saul’s bedroom door is closed and I leave a note, with keys, saying that I will be back on Friday evening ‘in time for chess and dinner’. He already knows the neighbourhood fairly well and will be able to buy milk and booze and British newspapers at the various shops I have pointed out over the last three days. Nevertheless, closing the door behind me feels like an act of the grossest negligence, every instinct I possess for privacy recklessly ignored. But for the impact on my Endiom career, I would immediately telephone Julian at home, explain that there has been a problem, and cancel the trip.

At my regular breakfast café on Calle de Ventura Rodríguez I eat a croissant, with a copy of The Times for company. The Kuwaiti desert is gradually filling with troops and tanks and the prospects for war look bleak: a long drawn-out campaign, and months to take Baghdad. Beside me at the bar a construction worker has ordered a balloon of Pacharán, iced Navarran liqueur, at 8 a.m. I content myself with an orange juice with just a splash of vodka and head outside to the car.

For €250 per month I keep the Audi on the second floor of an underground car park beneath Plaza de España, the vast square at the western end of Gran Vía dominated by a monument to Cervantes. It has been some time since I was last down here and a thin film of dust has formed on the bonnet and across the roof. I lift the spare wheel out of the boot, conceal the bag of money in the moulded recess, remove several CDs from my suitcase for the journey ahead and lay two suits flat along the back seat. A woman passes within ten feet of the car but walks by without so much as a glance. Then it’s just a question of finding the ticket and driving out into rush-hour Madrid. Cars have double-parked along the length of Calle de Ferraz, reducing a three-lane street to traffic that can only bump along in single file. The aggression of horns at this hour of the morning is jarring and I regret not having left an hour earlier. It takes twenty minutes to reach Moncloa and a further ten until we are at last loose on the motorway, bunched traffic moving clockwise on the inner orbital, heading north for Burgos and the N1. Low clouds have settled on the flat outer plains of Madrid, industrial plants and office blocks broken up by thin, dew-rich mists, but otherwise there is little to look at but endless furniture superstores, German technology companies and blinking roadside brothels. Living in the centre of Madrid, I forget the extent to which the city sprawls out this far, blocks of flats deposited on the featureless plain, built with no greater purpose than proximity to the capital. These could be the outskirts of any major city in the American Midwest. It does not feel like Spain.