‘Sorry, Mikel, sorry.’ My breathing is fast and irregular. ‘My phone started ringing down there and I wanted to take it. There’s this girl I’ve been seeing and the signal was weak…’

He doesn’t believe me. ‘What happened?’ he says gently.

‘Like I was just telling you. A girl…’

‘No, come on. What? You become scared by something?’

He is not angry. In fact he is being surprisingly sympathetic.

‘Scared?’ I produce an absurd burst of laughter. ‘No, of course not.’

‘You suffer claustrophobia, Alec?’

It’s an idea. I might as well play along rather than try to pretend that I received a mobile phone signal under fifty feet of concrete.

‘OΚ, to be honest, yes. I do. I got a bit freaked out. Call it claustrophobia.’

‘My brother has this as well.’ God bless Mikel Arenaza’s brother. ‘I am sorry, very sorry to hear about it.’ He shakes his head and puts a hand on the lower part of my neck, giving it a little squeeze. ‘You should have said something before we go.’

‘Well, I thought I’d outgrown it, Mikel, I really did. I haven’t had an episode like that for years. We bankers aren’t very tough, you know?’

He doesn’t laugh. ‘No, this is not funny. I know because of Julio. It ruins his life.’ Opening a widebrimmed umbrella, Arenaza shields me from the rain and assumes an almost avuncular air. ‘You want to rest? You want to go back to your hotel?’

‘No, of course not.’ He has applied a fresh layer of aftershave in the car park and I wish that we were not standing so close together. ‘Let’s carry on. Let’s have a drink. I’d like to, I really would.’

And he accepts, talking all the way about his own fears – of heights, of spiders – purely to lessen my own sense of embarrassment. It is an unarguably kind thing to do and I feel an unexpected sense of shame that I should have suspected him of anything but openness and decency.

‘This is where I want to take you,’ he says as we arrive outside an herrika taverna, back in the depths of the Parte Vieja. ‘Inside you will see the problems with the abertzale. Then it will all become clear.’

The small bar is jammed and thumps with the cacophonic roar of Basque heavy metal. A smell of marijuana hits me like a memory of Malasaña and Arenaza looks back as we drift past its source: two Goths sucking on a joint the size of a magic marker. He is greeted, though not warmly, by several of the customers, yet he stops to talk to no one. At the bar we turn to face one another and I insist that it’s my round.

‘We pay at the end,’ he says. ‘You’re not too uncomfortable here? Not too much crowd?’

He is harping back to the claustrophobia.

‘No, I’m fine. It’s more a fear of the dark, Mikel. Generally I’m all right in crowds.’

A woman is serving behind the bar with the sides of her head shaved and the hair grown out long at the back. It is a Basque style. Looking around, I can see half a dozen young men with similar cuts, and another three or four with what can only be described as mullets. The idea – according to a journalist I had lunch with in Villabona on Wednesday – is to present a stark contrast to the primped rugs of Madrid ’s young conservative elite, who tend to favour neat side partings or waves of sculpted gel. Arenaza leans over and kisses the barmaid on both cheeks, though again he is greeted coolly.

‘Let’s drink something,’ he says, ordering two large whiskeys – Irish, of course – with plenty of ice in mine. There is a small, blue-black pot on the bar, like an Inca urn, and I ask what it is.

‘That is a collection box,’ he replies quietly. ‘Money for our prisoners.’

‘For prisoners of E-T-A?’

‘Exactly.’

This catches me off guard.

‘That’s legal?’

Arenaza shrugs. I can see now that there are photographs of ETA prisoners all over the bar, hidden in corners next to ageing stickers promoting Batasuna, mug shots of ‘freedom fighters with self-conscious stares, gazing out in defiance at the insult of devolved power. About one in every five is a woman, and none of them can be much older than thirty. What must it be like to live with the day-to-day conviction of political violence, to take a human life in the name of a cause? Epiphany or no epiphany, Arenaza must have some experience of this; you do not work for Batasuna for sixteen years without drops of blood accumulating on your hands. It is in herrika tavernas like this one, all over the Basque country, that ETA firebrands will do a lot of their recruiting, pouring nationalist propaganda into the ears of susceptible young men who will later go off to bomb the hotels of British tourists in Alicante, or to blow up the cars of a politician or judge brave enough to have taken a stand against the ‘armed struggle’. Is that how he started out? Was Arenaza talent-spotted as a teenage terrorist, later to send out acolytes of his own on the path to an ignorant martyrdom?

‘Would you like something to eat?’ he asks.

‘I’m not hungry.’

As if on cue my mobile phone trills and a text message comes through from Sofía:

Miss u tonight. Hope u are being careful in the north.

Be aware of the basques. They are fascists. xxx

‘Is everything all right?’

I switch off the phone.

‘Everything’s fine. Still feeling a bit strange from the car park.’

He picks up our drinks and finds a corner in which to stand and talk.

‘Tell me something,’ I ask him, feeling like I want to have this out. ‘Are these bars used for money laundering? If I buy you a whiskey or a bocadillo, am I helping to pay for a detonator on E-T-A’s next car bomb?’

He appears to admire my frankness.

‘Well, it is true, up to a point. What is the reason for denying this? A lot of people are engaged in the war, Alec. A lot of people want to see an independent Basque state.’

‘And a lot of people just want to be left in peace. Most people want to have nothing whatsoever to do with politics. You said so yourself, just half an hour ago.’

‘It’s true, it’s true.’ He looks suddenly disgusted by his cigarette and extinguishes it in an ashtray. ‘Politics is over for the great majority. We have talked about this. The complete irrelevance of political discourse of any kind. This is why an event like 9/11 comes as such a shock to the average American. “Who are these people?” they ask themselves. “What have we done to them that they can do this to us?” People are ignorant of the facts. They are misinformed by journalists on the television and in the newspapers, and anyway they do not care. If they did, they would seek answers. If they did, they would take to the streets.’

‘But Spanish people never stop taking to the streets. There are protests in Madrid all the time. I can’t hear myself think in Calle Princesa at the moment. Every time I look out of the window there are 10,000 people protesting against the war in Iraq.’

He smirks. ‘And they will not be heard. It is only a story that fills news programmes, something to give people a subject to talk about over lunch. This protest makes them feel good, as if they have done something. But it is just the orgasm of the collective act, a masturbation.’ Arenaza mispronounces this word and I almost laugh. ‘Take away that person’s television, their car, their house, then you will see them commit to a cause.’

‘But that’s the position here in Euskal Herria. You insist, in spite of all the freedoms enjoyed by modern Basques, that Spain has stolen something from you. Your country. And yet you’ve given up – on yourself and on the people. You think democracy and freedom of speech are wasted on them.’

This gives Arenaza pause, as if I have locked him in a contradiction, and again I begin to wonder whether he really believes anything he says. It all seems so cynical, so reductionist, so completely at odds with the confident, Madrid-bashing nationalist of first acquaintance. Has he been told to say it?