Restless

'I still don't follow.'

He explained: towards the end of 1941, NKVD interest began to focus on the strenuous efforts that the British were making to persuade the USA to ally themselves with Britain and Russia against the Nazis. These efforts seemed to be working: to the Russians it appeared as if Roosevelt was looking for any excuse to join the war in the Allied cause. The discovery of the Brazilian map was a key factor in this propaganda war – it seemed to have genuinely tilted the balance. A great coup by BSC, so it was judged. US public opinion could understand much better a threat that lay at their own borders, rather than one that was a distant 3,000 miles away.

So, Thoms argued, it was probably at this juncture that whoever was ru

'So Sage was meant to be the smoking gun,' I said. 'BSC exposed – perfidious Albion, yet again.'

'Yes, but Mr A's hands were totally clean. It was a brilliant, very, very clever operation. Mr A issued no instructions to Sage beyond the initial courier delivery – everything Sage did on the way to New Mexico and in Las Cruces was impromptu, completely unpla

Engineer her own destruction, I thought – but she was too smart for them all.

'Anyway, it didn't matter in the end,' Thoms said, with a wry smile. 'The Japanese came to the rescue with the attack on Pearl Harbor – and so did Hitler with his subsequent unilateral declaration of war on the USA a few days later: everyone tends to forgets about that… Everything changed, for ever. All this made sure that, even if Sage had been compromised, it would have made no difference at all. The US was finally in the war. Mission accomplished.'

Thoms had made a few other points. He felt that the assassination of Nekich seemed very significant. Information from the FBI debriefing of Nekich appeared to have reached Morris Devereux in November 1941, hinting about serious Soviet penetration of the British security and intelligence services ('We know now just how extensive it was,' Thoms added, 'Burgess, Maclean, Philby and whoever else in the gang is still lurking out there'). Devereux would never have suspected Mr A as a 'ghost' had not agent Sage's experiences in Las Cruces caused grave doubts to be raised and the finger of culpability to be pointed. Devereux was clearly very close to unmasking Mr A before he was killed. His death – his 'suicide' – bore all the signs of an NKVD assassination squad, which again supported the case for Mr A being a Russian agent, rather than German.

'I think Mr X is probably Alastair De

'In what way?'

'Well, this is the real dividend of the stuff you gave me. It would be shocking if it was made public. Huge scandal.'

I said nothing more. He asked me if I wanted to go out for a meal some time and I said I would call – life was a bit frantic at the moment. I thanked him very much and drove out to Middle Ashton, picking up Jochen on the way.

My mother seemed to have reached the final page. She read out loud: '"However, this is not to denigrate the story of agent Sage. The material you gave me provides a fascinating account into both the huge extent and the minutiae of BSC operations in the USA. This is all compelling stuff to someone like me, needless to say – the lid has been kept very firmly pressed down on what the BSC was up to over the years. Until now, no one on the outside has really had any idea of the extent of British intelligence operations in the USA before Pearl Harbor. You can imagine how this information might be received by our friends on the other side of the Atlantic. Forging a 'special relationship' clearly wasn't enough – we needed British Security Coordination to go the extra mile."'

She tossed the pages down on to the grass; she seemed upset and stood up, ran her hands through her hair and went into the house. I didn't go to her – I thought she probably needed some time to let all this analysis filter through to her, to see if it fitted, made sense.

I reached over and picked up the typed pages, tapping them into shape on my knee, deliberately thinking about other things, such as the intriguing news the morning's post had brought – an invitation to the marriage of Hugues Corbillard and Bérangère Wu in Neuilly, Paris, and another letter from Hamid, sent from a town called Makassar on the island of Celebes, Indonesia, a

My mother came back out of the house, a packet of cigarettes in her hand. She seemed more composed as she sat down, offered me one (which I refused, I was trying to give up, as a result of Jochen's persistent nagging).

I looked at her and watched her light her cigarette.

'Make any sense, Sal?' I asked, tentatively.

She shrugged. 'How did he express it? "The minutiae of BSC operations in the USA…" I suppose he's right. Suppose de Baca had killed me – it wouldn't have made any difference. Pearl Harbor was right around the corner – not that anybody ever guessed it would happen.' She managed a chuckle, but I could tell she didn't find it fu

I thought for a while and then said, ' Roosevelt never made that speech, did he? When he was going to use your Mexican map as evidence. That would have been amazing – might have changed everything.'

'You're very kind, darling,' my mother said. I could tell she was not going to be bucked up today whatever I tried: there was a kind of resigned weariness about her – too many unhappy memories swirling around. ' Roosevelt was due to make the speech on 10 December,' she said. 'But then Pearl Harbor happened – and he didn't need a Mexican map anymore.'

'So Thoms is saying that Romer was a Russian agent. Like Philby, Burgess, Maclean – I suppose that's why Romer killed himself. Too old to run like they did.'

'It makes more sense,' she said. 'I could never understand why Morris thought he was an Abwehr ghost.' She smiled an empty smile. 'Still,' she added with heavy irony, 'it's good to know how insignificant and petty it all was in the "big picture", I must say.'

'It wasn't insignificant and petty to you,' I said, putting my hand on her arm. 'These things all depend on your point of view. You were the one in the desert with de Baca – no one else.'