‘But that’s not their fault.’ I don’t like hearing this from a politician, conviction or no conviction. ‘Democracy isn’t wasted on the public just because they don’t have a voice. It’s wasted on the politicians who take advantage of them.’

‘Exactly, exactly.’ Arenaza appears to agree wholeheartedly and drains his drink. ‘But the idea that governments listen to the public, that they are accountable to the men and women who voted for them, is a notion from the nineteenth century, in your country from the beginnings of socialism when people finally had a voice and a way of communicating with each other. Before that politics was about the special interests of elites. People forget this, and now we are back at this point. Your British government pursues a policy based on one simple ideology: follow America. That is the extent of their imagination. And in the long run it is easier for Mr Blair to say “No” to hundreds of thousands of British voters, even to ignore the voice of his own conscience, than it is for the Foreign Office of the United Kingdom to say “No” to George Bush. Now, follow my logic. Once the prime ministers of Spain and of the UK have a decision of this kind forced upon them, that is to say they have no choice in what they do because of America, then they start to see themselves as men of destiny. Good Europeans against bad, friends of democracy against friends of terror. The ego takes over.’

I’ve lost the thread here, but find a question. ‘So why are you still involved in politics?’

‘I am not. We have been banned.’

‘Yes, but -’

‘Listen to me. I have sat in on these meetings, even at the level of local politics, and none of my superiors ever cared for anything but their own personal and political advancement. They are all little Dick Cheneys, all the same. Politics is the vanity of individual men. Policy is shaped by flaws in the character.’

Why is he telling me this? Because he is drunk? ‘You’re saying that you disapprove of your colleagues?’

A heavy pause. Arenaza runs his hand through a thick clump of hair.

‘Not exactly, no. Not disapprove.’ I suppose he doesn’t want to overstep the mark. ‘It is more a question of human nature, of reality. Listen, you have somewhere else you have to go tonight?’

‘No.’

‘Then come with me. I will explain everything to you. We go to another bar and I will show you exactly what it is that I mean.’

A light drizzle has started to fall by the time we leave the bar, the dark, narrow streets of the old quarter coated in black rain. The sea air is damp, Atlantic, quite different from the dry and dusty atmosphere of Madrid, and to take it in deep breaths is a welcome relief after the fug of the bar. Moving quickly beside Arenaza as we walk along the street I try to anticipate what the next few hours might hold. Anything could happen. The evening may disappear in a mulch of booze and ideology, or it could acquire a completely different character. Unless I have read the situation wrongly, Arenaza appears to have undergone some sort of political epiphany, criticizing his former masters in the armed struggle and happily articulating that revelation to strangers such as myself. It is the aeroplane phenomenon: the most sensitive information is often disclosed to the passenger sitting by our side whom we expect never to see again. As Arenaza spoke to me in the bar, confidence seemed to ebb away from him with each passing drink, as if a mask were slipping from his face. On the basis of a shared acquaintance with Julian, a former councillor with Batasuna was taking me into his confidence, and yet it somehow made perfect sense. I charmed him back there. I worked him round.

‘First we have to go to my car,’ he says. ‘I have to take off this jacket, Alec, to change out of my suit and shoes. You OK if I do this?’

‘No problem.’

Most of the better bars and restaurants in San Sebastián are clustered around the Parte Vieja, but I have spent very little time here, largely because Julian’s contacts preferred to meet in the lounge bar of the Hotel Inglaterra, where the comfortable sofas and armchairs offer views out onto the promenade and the ocean beyond. As a result, I don’t know my way around and Arenaza’s frequent switches of direction along the grid of streets are disorientating. It feels as though we are heading west towards the Concha, but it is impossible to take a bearing. Arenaza is holding a copy of the Gara newspaper over his head to protect it from rain, using his other hand to talk into a mobile phone. He is speaking to someone rapidly in Basque:

‘Denak ondo dago. Gaueko hamabietan egongo maizetxean. Afari egin behar dut Ingles bankari honekin.’

Who is he talking to? His wife? A colleague? Halfway through the conversation he breaks off and gestures at a poster tacked to the window of a nearby bar. It is a cartoon depicting a caricature of Aznar, the prime minister’s tongue curling deep into the arse of President George W. Bush. The caption is written in Basque and I cannot understand it. Through the window I can see two men playing chess on stools. Arenaza mouths the word ‘Truth’ and continues speaking into the phone. ‘Ez arduratu,’ he says. ‘Esan dizut dagoenekoz. Gaueko hamabiak. Bale ba, ikusi ordu arte.’

Then the conversation ends and we emerge into a pedestrianized area immediately behind the town hall. It is past nine o’clock and the streets are teeming with people. Arenaza explains that his car is parked in an underground garage about fifty metres away. Putting his hand on my back, he steers me across a set of blinking pedestrian lights and we walk towards the entrance.

‘Down here,’ he says. ‘Down here.’

The staircase is poorly lit and I hold on to the banister, pushed aside at one point by a pensioner coming the other way wearing a fake mink coat. The car park is on three subterranean levels, each one increasingly damp. Arenaza’s car, a tiny, door-dented Fiat, is parked in the far corner of the bottom floor, squeezed in between a brand-new Mini Cooper with British plates and a dark blue Renault Espace. This must be the long-term car park, because the area is completely devoid of people. It is very dark now, and for the first time it occurs to me that I may have completely misread the situation. Why did Arenaza need me to come all the way down here? Why is he changing his clothes?

‘You know what, Mikel, I think I might wait upstairs.’ This could be a kidnap attempt, a robbery, anything. ‘I’ll see you at the entrance to the town hall.’

I should never have come here of my own volition. I’m letting things slip.

‘What are you saying?’ He sounds relaxed, fishing around in the boot of the Fiat, his face is out of sight. ‘Alec?’

‘Just that I need to make a phone call. From the entrance. To a friend in Madrid. She’s trying to call me. I’ll see you at the top, Mikel, OK? I’ll see you at the top.’

‘Wait, wait.’ He emerges between the Fiat and the Mini, dressed in an old sweater worn over a clean white T-shirt. ‘You’re going upstairs? Can you wait just for two minutes please?’

I back away from the car and spin slowly through a complete turn, trying to read his eyes. In the distance, something metal drops to the ground. It is too dark and very quiet. Just the concrete chill of basements and a pervasive smell of spilled petrol. Then, thirty feet away, two men emerge quickly from a van and start moving towards me. Immediately I turn and run back towards the exit staircase, with no thought other than to get out as quickly as possible. Behind me, Arenaza shouts out ‘Hey!’ but I do not respond, sprinting hard up three flights of stairs and into the blessed relief of rain and fresh air.

At street level I bend down and double up in the crowds, resting my hands on my knees in an attempt to catch some breath. Why did Julian set me up with this guy? My head aches and the backs of my legs are shaking. Then, behind me, the two men emerge onto the street, walking at a steady pace. With a sense of relief that quickly changes to shame, I see that they are Chinese. Not Basque nationalists, not errand boys for ETA, but two tourists wearing denim jeans and raincoats. One of them is telling a story, the other laughing while consulting a map. It is humiliating. Seconds later Arenaza himself emerges, looking around with an expression of complete bewilderment. How do I get out of this one? I take out my mobile phone, press it to my ear and say the words ‘Two three four five, two twos are four, two threes are six’ in an attempt to give an impression of urgent conversation. Arenaza spots this and frowns. I wave happily back, gesturing to the phone, and then snap it shut as he comes towards me.