‘Who is Luis Buscon?’ she asks, trying to breathe deeply, trying to control herself. ‘Who is Luis Buscon?’ I am about to answer her when she adds, ‘I get a phone call at work last night telling me to come to the Hotel Carta this morning to pick up a box of samples left by somebody called Abel Sellini. He says that he represents an Italian designer. I didn’t know who he was. He said it was important. Who is Luis Buscon? Alec, what is this about?’

It starts to make sense. ‘What was in the package?’ I ask. ‘Tell me. What was in it, Sofía?’ I am hurrying her as she stares at me, desperate to have her betrayal disproved. She watches every tic of my face as she retrieves her handbag from the floor. Inside there is a letter which she takes out of an envelope, thrusting the single page into my hands like evidence of an adultery.

‘What is this?’

‘Léelo,’ she says.

Read it.

The letter is unsigned and badly typed. It consists of one simple sentence, written in Spanish:

Tell your boyfriend to stop what he is doing or your nice English husband will find out that he is married to a Spanish whore.

‘There were photographs as well,’ Sofía says, beginning to cry again, and suddenly it all makes sense. None of what has happened has anything to do with Katharine or Fortner, with Nicole or Julian. Sofía hasn’t betrayed me. But my immediate elation is checked by the knowledge that Buscon knew about our affair. He and his colleagues must have been following me for weeks. ‘I destroyed them,’ Sofía is saying. ‘There were pictures of you and me in Argüelles, Alec, photographs taken through the window of your apartment when we were kissing, pictures of me walking beside you in Princesa. Who are you? Who would blackmail us like this? Is it something to do with your work for Julian? How do you know that I went to the hotel this morning? Have you been following me?’

I have to construct a lie even as I am putting together the final pieces of the jigsaw. It has all been a terrible misunderstanding. I have to find a way of protecting Kitson’s operation.

‘It’s to do with the men in Zaragoza,’ I tell her. ‘I can’t tell you any more than that.’

‘The men that fought you?’

‘The men that attacked me, yes.’

‘Eres un mentiroso.’ She shakes her head and looks away towards the window. ‘You lie all the time. I want to know the truth.’

‘I am telling you the truth. This is something private that I’m involved in. It’s a big real-estate deal. I’ve saved a lot of money since my parents died and if I invest it in this project I could make hundreds of thousands of euros. But there are people who are trying to stop me.’

‘This Luis Buscon? This Abel Sellini?’

‘Exacto.’

‘Who are they?’

‘They are businessmen, Sofía. Sellini and Buscon work for a Russian company in Marbella.’

‘For the mafia?’ She looks aghast. I have dragged her into a nightmare.

‘I don’t know if they’re mafia. I suppose they are. I met them as part of my work for Endiom. But Julian doesn’t know anything about it. You can’t tell him.’

‘I’m not going to tell him,’ she spits. ‘You think I am going to tell my husband about us? You think so, Alec? Is this what you would do? Show me what these men did to you. Show me the marks on your body.’

‘There are no marks.’

But she is tearing at my clothes, tugging at the buttons so that one of them falls loose and flies free of my shirt. It is quite dark in the room and her reaction to the bruising on my chest is not as awful as it might have been. She just bites her lip and juts out her chin, eyes stung by shock.

‘Dios mío, qué te han hecho?’ Sofía arrives at an immediate decision, shaking her head. ‘You have to stop this thing now, Alec. These people are very serious. I do not want any more letters. I do not want any more photographs. I do not want them to hurt us. They will kill you next time, no? I want you to promise me that you will stop this.’

‘I promise you that I will stop this.’

And we are finished. It is over between us. I cannot see you any more.’

I suppose I am touched by the fact that she trips on these words, but a stubborn part of me won’t let her leave. I need her now, more than I have ever done, if only to be comforted by her. I cannot be alone any longer.

‘Don’t say that. Please don’t overreact. If I pull out of the deal they’ll leave us alone.’ I attempt to hug her, but she twists her body away from mine as if I am still hateful to her. ‘What’s the matter?’

‘Don’t touch me!’ She looks at me with such contempt. ‘You think I want to touch you after you involve me with this? You have never told me the truth about anything.’

But in the same movement she returns to me, placing her arms around my back so that I can pull her towards me. She is suddenly beautifully still, defeated, her face turned against my chest. Her hair smells so beautiful as she tries to find her breath. I kiss her head, breathing in the sweet caress of her forgiveness, saying, ‘Lo siento, mi amor, lo siento. Por favor perdóname,’ but wondering all the time if this woman is still playing me for a fool. ‘I didn’t mean to hurt you,’ I tell her. ‘I had no idea that they would threaten you.’

And she says, ‘I need you, Alec. I hate you. I cannot leave,’ and tilts her head to kiss me.

34. House of Games

I sleep for thirteen hours straight, beyond Sofía’s leaving, beyond check-out at the hotel. It is the middle of Tuesday afternoon by the time I wake up, as if from a coma, wrapped in a warm sweat of deep relaxation. For a long time I simply lie in bed staring at the bad paintings on the walls, enjoying a rare sensation of total restedness. Kitson asked me to call him with an update on the Sofía situation, but I run a bath first and order coffee and scrambled eggs from room service before dialling his number.

‘Best if you come direct to the safe house,’ he says, ‘the flat in Tetuán.’ He texts the address to my mobile.

Kitson’s team have set themselves up in a cramped apartment block in Barrio de la Ventilla, about two kilometres north-west of the Kia towers. I take the Line 10 metro two stops beyond Plaza de Castilla to Begoña, where I hail a cab and instruct the driver to loop anticlockwise around the Parque de la Paz en route to Vía Límite. There’s no surveillance problem, but I walk the last two blocks just to be certain and arrive a short time after five o’clock.

‘Sleep well?’ Kitson asks as he greets me at the door.

‘Like Sonny von Bülow,’ I reply, and he smiles, ushering me into the flat.

Four spooks – two men, two women – are gathered around a small Formica-topped table in the kitchen. I recognize two of them immediately: lead on Macduff, and the woman from the tyre garage near Moby Dick. All four look up from cups of tea and smile, as if at an old, familiar friend.

‘You’ll all recognize Alec Milius,’ Kitson says, and I’m not sure if this is just small talk or a dig at my counter-surveillance technique. Either way, I’m irritated by it; it makes me look second-rate. Macduff is the first to respond, rising from his seat to shake my hand.

‘Anthony,’ he says. ‘Good to meet you.’

I was expecting something altogether different, a voice to match the bustling military gent encountered at the Prado, but that was obviously cover. Anthony has a scrambled accent – Borders, at a guess – and is dressed in stonewashed jeans with a black Meat Loaf T-shirt. Tyre lady is next, too boxed in at her seat to be able to stand, but honouring me with a look of real admiration as she stretches to shake my hand.

‘Ellie,’ she says. ‘Ellie Cox.’

The other man is Geoff, the woman, Michelle. The latter is under thirty and on secondment from the Canadian SIS. Kitson mentioned running a team of eight, so the other four must be out tracking Buscon. I am offered tea, which I accept, and sit down on a low pine bench at the head of the table. To my surprise all of them look a little bored and washed-out, and there’s a strange end-of-term atmosphere to the gathering. If they are suspicious of me, they do not show it; if anything, they seem grateful to welcome a new face into their world, somebody unknown whom they can analyse and work out. Bottles of gin and mineral water and Cacique are lined up along a narrow shelf above Ellie’s head, with cans of baked beans, some Hob Nobs and a pot of Marmite peeking out of a cupboard near the cooker. Geoff has a British car magazine open on the table in front of him and spills a little milk on it as he pours my tea. Plates and mugs are drying on a metal rack beside the sink and behind me there’s a clothes horse swamped in laundry. It must be a tight squeeze living in here with four colleagues; they must get on each other’s nerves.