All of the shame and despair and regret that I have experienced since Kate’s death is crystallized in this instant. Saul’s face is as hard and as unforgiving as I can ever remember seeing it. It is the end of our friendship. With just a few stark sentences he has engendered a violent and sudden cut-off.

‘So that’s it?’

‘That’s what?’

‘The end of things between us? That’s what you came out here to tell me? That it’s better if I don’t contact you any more?’

‘What the fuck are you talking about?’

‘You said it yourself. I’m a liar, a manipulator. I’m a footnote.’

‘That doesn’t mean it’s the end of our friendship.’ Saul looks at me in amazement, as if I have completely misjudged both him and the situation. ‘Jesus, we’re not at school any more, Alec. This isn’t a playground.’ I stare down at the table and cradle the back of my neck, bewildered and embarrassed. ‘Short of you developing an all-new fixation with Catalan schoolboys we’re still going to be mates. Things don’t end between people just because they betray them. In fact, that’s probably when they start to get interesting.’ There is a long burst of applause from the next-door room. ‘Let’s face it, we’re always more grateful to the people who have hurt us in life than to the ones who just let things drift by. I learned from you, and that’s what it’s all about. I’m just not going to sit here and let you think that no harm came from what happened…’

‘Believe me, I don’t think that for a second.’

‘Let me finish. It’s important for me to say this to you, face to face. I don’t get the chance on email. I don’t get the chance on the phone.’

‘OK.’

‘What you did was wrong. You didn’t kill Kate or Will, but your work and your lying led to their deaths. And I don’t see you doing anything out here to put that right. I don’t see you making amends.’

Ordinarily I might challenge Saul on this. Make amends? Who is he to speak to me this way? I make amends with my solitude. I pay penance with exile. But he has always believed in the myth of self-improvement; any reasoning I might employ would only burn out in the fire of his moral authority. We find ourselves eating in silence, as if there is nothing left to be said. I could try to defend myself but it would only feel like a tactic, a lie, and Saul would jump on it as quickly as he leaped on my earlier defence. At the next table the grandparents are standing up with considerable effort, having paid their bill and left just a few small coins as a tip. At the base of their receipt it says ‘No A La Guerra ’ and the waiter has written ‘Gracias’ in felt-tip pen. The husband helps his wife into a garish fur coat and casts both of us an inscrutable smile. Perhaps he understood English after all. For once, I do not care.

‘Jesus!’

Saul has bitten into a hot padrón and downs an entire glass of wine to kill the heat.

‘You OK?’

‘Fine,’ he says, pursing his cheeks. ‘We need more booze.’

And this small incident seems to break the spell of his disquiet. A second bottle comes and we spend the rest of the meal talking about Chelsea and Saddam Hussein, about Saul’s grandfather – who has lung cancer – and even Heloise, whom he is inclined to forgive in spite of her blatant adultery. I note the double-standard in his attitude to the two of us and wonder if there is something saintly in Saul which actually encourages people to betray him. There has certainly always been an element of masochism in his personality.

With coffee, the waiter brings us two small shots of lemon liqueur – on the house – and we down them in a gulp. Saul is keen to pay (‘as a present, for putting me up’) and I feel mildly drunk as we make our way out past the kitchen and into the bustle of Chueca. It is past midnight and the nightlife is well under way.

‘You know a decent bar?’ he asks.

I know plenty.

Spaniards dedicate so much of their lives to enjoying themselves that a word actually exists to describe the span of time between midnight and 6 a.m., when ordinary European mortals are safely tucked up in bed. La madrugada. The hours before dawn.

‘It’s a good word,’ Saul says, though he thinks he’ll be too drunk to remember it.

We leave Chueca and walk west into Malasaña, one of the older barrios in Madrid, still a haunt of drug dealers and penniless students though, by reputation, neither as violent nor as rundown as it was twenty years ago. The narrow streets are teeming and dense with crowds that gradually thin out as we head south in the direction of Gran Vía.

‘Haven’t we just been here?’ Saul asks.

‘Same neighbourhood. Further south,’ I explain. ‘We’re going in a circle, looping back towards the flat.’

A steep hill leads down to Pez Gordo, a bar I love in the neighbourhood, favoured by a relaxed, unostentatious crowd. There’s standing room only and the windows are fogged up with posters and condensation, but inside the atmosphere is typically rousing and flamenco music rolls and strums on the air. I get two cañas within a minute of reaching the bar and walk back to Saul, who has found us a spot a few feet from the door.

‘Do you want to hear my other theory?’ he says, jostled by a customer with dreadlocked hair.

‘What’s that?’

‘I know the real reason you like living out here.’

‘You do?’

‘You thought that moving overseas would give you a chance to wipe the slate clean, but all you’ve done is transfer your problems to a different time zone. They’ve followed you.’

Here we go again.

‘Can’t we talk about something else? It’s getting a little tedious, all this constant self-analysis.’

‘Just hear me out. I think that some days you wake up and you want to believe that you’ve changed, that you’re not the person you were six years ago. And other times you miss the excitement of spying so much that it’s all you can do not to ring SIS direct and all but beg them to take you back. That’s your conflict. Is Alec Milius a good guy or a bad guy? All this paranoia you talk about is just window-dressing. You love the fact that you can’t go home. You love the fact that you’re living in exile. It makes you feel significant.’

It amazes me that he should know me so well, but I disguise my surprise with impatience.

‘Let’s just change the subject.’

‘No. Not yet. It makes perfect sense.’ He’s toying with me again. A girl with a French accent asks Saul for a light, and I see that his nails are bitten to the quick as she takes it. He’s grinning. ‘People have always been intrigued by you, right? And you’re playing on that in this new environment. You’re a mysterious person, no roots, no past. You’re a topic of conversation.’

‘And you’re pissed.’

‘It’s the classic expat trap. Can’t cope with life back home, make a splash overseas. El inglés misterioso. Alec Milius and his amazing mountain of money.’

Why is Saul thinking about the money?

‘What did you say?’

A momentary hesitation, then, ‘Forget it.’

‘No. I won’t forget it. Just keep your voice down and explain what you meant.’

Saul grins lopsidedly and takes off his coat. ‘All I’m saying is that you came here to get away from your troubles and now they’ve passed you by. It’s time for you to move on. Time for you to do something.’

For a wild moment, undoubtedly reinforced by alcohol, it crosses my mind that Saul has been sent here to recruit me, to lure me back into Five. Like Elliott sent to Philby in Lebanon, the best friend dispatched at the state’s request. His angle certainly sounds like a pitch, although the notion is ridiculous. More likely Saul is simply adhering to that part of his nature that has always annoyed me and which I had somehow allowed myself to forget; namely, the moralizing do-gooder, the self-righteous evangelist busily saving others whilst incapable of saving himself.