'Has she seen a doctor?'

'Oh, yes. She convinced the doctor about her back – he provided the wheelchair.' I thought for a moment and then decided to tell her the rest. 'She says she was recruited by the British Secret Service in 1939.'

Veronica had to smile at that, then looked baffled. 'But otherwise she seems perfectly normal?'

'Define "normal",' I said.

We parted and Jochen and I wandered along Moreton Road to the dentist's. Mr Scott was easing himself into his new Triumph Dolomite; he eased himself out and made some show of offering Jochen a mint – he always did this when he saw Jochen, Mr Scott being constantly well supplied with mints of various sorts and brands. As he backed out of the drive we walked down the alley at the side of the house to 'our stepway', as Jochen called it, set at the back, a wrought-iron staircase that gave us our own private access to our flat on the first floor. The disadvantage was that any visitor had to come through the kitchen but it was better than going through the dentist's below with its strange pervasive smells – all mouthwash, dentifrice and carpet shampoo.

We ate cheese on toast and baked beans for supper and watched a documentary about a small round orange submarine exploring the ocean floor. I put Jochen to bed and went through to my study and found my file where I kept my unfinished thesis: 'Revolution in Germany, 1918-1923'. I opened the last chapter – 'The Five-Front War of Gustav von Kahr' – and, trying to concentrate, scanned a few paragraphs. I hadn't written anything for months and it was as if I was reading a stranger's writing. I was fortunate that I had the laziest supervisor in Oxford – a term could go by without any communication between us – and all I did was teach English as a Foreign Language, look after my son and visit my mother, it seemed. I was caught in the EFL trap, all too familiar a pitfall to many an Oxford postgraduate. I made ?7 an hour tax-free and, if I wanted, I could teach eight hours a day, fifty-two weeks of the year. Even with the constraints on my time imposed by Jochen I would still make, this year, more than ?8,000, net. The last job I had applied for, and failed to get, as a history lecturer at the University of East Anglia was offering a salary (gross) of approximately half what I earned teaching for Oxford English Plus. I should have been pleased at my solvency: rent paid, newish car, school fees paid, credit card under control, some money in the bank – but instead I felt a sudden surge of self-pity and frustrated resentment: resentment at Karl-Heinz, resentment at having to return to Oxford, resentment at having to teach English to foreign students for easy money, (guilty) resentment at the constraints my little son imposed on my freedom, resentment at my mother suddenly deciding to tell me the astonishing story about her past… It had not been planned this way: this was not the direction my life was supposed to have taken. I was twenty-eight years old – what had happened?

I called my mother. A strange deep voice replied.

'Yes.'

'Mummy? Sal? – It's me.'

'Is everything all right?'

'Yes.'

'Call me right back.'

I did. The phone rang four times before she picked it up.

'You can come next Saturday,' she said, 'and it'll be fine to leave Jochen – he can stay the night, if you like. Sorry about last weekend.'

'What's that clicking noise?'

'That's me – I was tapping the receiver with a pencil.'

'Why on earth?'

'It's a trick. It confuses people. Sorry, I'll stop.' She paused. 'Did you read what I gave you?'

'Yes, I would have called earlier but I had to take it all in. Needed some time… Bit of a shock, as you can imagine.'

'Yes, of course.' She was silent for a while. 'But I wanted you to know. It was the right time to tell you.'

'Is it true?'

'Of course, every word.'

'So that means I'm half Russian.'

'I'm afraid so, darling. But only a quarter, actually. My mother, your grandmother, was English, remember?'

'We have to talk about this.'

'There's much more to come. Much more. You'll understand everything when you hear the rest.'

Then she changed the subject and asked about Jochen and how his day had been and had he said anything amusing, so I told her, all the 'while sensing a kind of weakening in my bowels – as if I needed to shit – provoked by a sudden and growing worry about what was lying up ahead for me and a small nagging fear that I wouldn't be able to cope. There was more to come, she had said, much more – what was that 'everything' that I would eventually understand? We talked some more, blandly, made our appointment for next Saturday and I hung up. I rolled a joint, smoked it carefully, went to bed and slept a dreamless eight hours.

When I returned from Grindle's the next morning, Hamid was sitting on the top step of our staircase. He was wearing a short new black leather jacket that didn't really suit him, I thought, it made him look too boxy and compact. Hamid Kazemi was a stocky, bearded Iranian engineer in his early thirties with a weightlifter's broad shoulders and a barrel chest: he was my longest-serving pupil.

He opened the kitchen door for me and ushered me in with his usual precise politesse, complimenting me on how well I looked (something he'd remarked on twenty-four hours previously). He followed me through the flat to the study.

'You haven't mentioned my jacket,' he said in his direct way. 'Do you not like it?'

'I quite like it,' I said, 'but with those sunglasses and black jeans you look like you're a special agent for SAVAK.'

He tried to cover up the fact that he didn't find this comparison amusing – and I realised that for an Iranian it could be a joke in dubious taste so I apologised. Hamid, I remembered, hated the Shah of Iran with special fervour. He removed his new jacket and hung it carefully on the back of his chair. I could smell the new leather and I thought of tack rooms and saddle polish, the redolence of my distant girlhood.

'I received the news of my posting,' he said. 'I shall go to Indonesia.'

'I am going to Indonesia. Is that good? Are you pleased?'

'Am going… I wanted Latin America, even Africa…' He shrugged.

'I think Indonesia sounds fascinating,' I said, reaching for The Ambersons.

Hamid was an engineer who worked for Dusendorf, an international oil engineering company. Half the students at Oxford English Plus were Dusendorf engineers, learning English – the language of the petroleum industry – so they could work on oil-rigs around the world. I had been teaching Hamid for three months now. He had arrived from Iran as a fully qualified petro-chemical engineer, but virtually monoglot. However, eight hours of one-on-one tuition a day shared out between four tutors had, as Oxford English Plus confidently promised in their brochure, made him swiftly and completely bilingual.

'When do you go?' I asked.

'In one month.'

'My God!' The exclamation was genuine and unintended. Hamid was so much a part of my life, Monday to Friday, that it was impossible to imagine him suddenly absent. And because I had been his first teacher, because his very first English lesson had been with me, somehow I felt I alone had taught him his fluent workmanlike English. I was almost his Professor Higgins, I thought, illogically: I had come to feel, in a funny way, that this new English-speaking Hamid was all my own work.

I stood up and took a hanger off the back of the door for his jacket.

'It's going to lose its shape on that chair,' I said, trying to disguise the small emotional turmoil I was feeling at this news of his impending departure.

As I took the jacket from him I looked out of the window and saw, down below on the gravelled forecourt, standing beside Mr Scott's Dolomite, a man. A slim young man in jeans and a denim jacket with dark brown hair long enough to rest on his shoulders. He saw me staring down at him and raised his two thumbs – thumbs up – a big smile on his face.