'The Restaurant,' I said. 'Not the Grill. Tessa never sees any of her friends in the Grill.'

Tessa arrived looking magnificent. She was thirty-three years old but she looked ten years younger than that. Whatever Tessa was doing, it seemed to be good for her. She had wonderful skin and light fair hair that she wore long so that it broke over her shoulders. George's income, to say nothing of the allowance she got from her father, was to be seen in every expensive stitch of the dark-blue Chanel suit, the Hermes handbag and Charles Jourdan shoes. Even the most blase waiter turned his head to watch her as she kissed me with extravagant hugs and sighs before sitting down.

She kicked off a shoe under the table and swore softly as she rubbed her foot. 'What a wonderful table you've got for us. With that lovely view of the river. They must know you.'

'No,' I said truthfully. 'I mentioned George's name as you suggested.'

She smiled dutifully as at an oft-repeated joke. She waved away the menu without looking at it and ordered an Ogen melon and a grilled sole with a small mixed salad. When she saw me looking down the wine list she said, 'Would you think me awful if I asked you to order a bottle of Bollinger, darling? My doctor has told me to avoid red wines and all other sorts of booze.'

'A bottle of Bollinger,' I told the waiter.

'I saw David,' she said. She rubbed her foot again. 'He's an absolute bastard, isn't he?'

'We've never got along very well together,' I said.

'He's a bastard. You know he is. And now he's trying to get the children. I hope you told him to go straight to hell.'

'I wouldn't like him to have the children,' I said.

'I wouldn't allow the old bastard to run a zoo,' said Tessa. 'He ruined my life and I blame him for what happened to Fiona.'

'Do you?'

'Well, don't they say all these spies and traitors are just reacting to the way they hate their parents?'

'It is a popular theory,' I said.

'And my father is living evidence of the truth of it. Who could imagine poor old Fi working for the rotten commies unless she'd been driven to it by David?'

'I'm keeping the children with me,' I said. 'It will be difficult to afford it, but no more difficult than it was for my father.'

'Good for you, Bernie. I was hoping you'd say that, because I'm going to help you, if you'll let me.' She looked at me with a stern expression that I found so appealing. It was impossible not to compare her with the diamond-hard Zena. But despite her sophisticated lifestyle and smart back-chat Tessa was insecure. Sometimes I wondered if her casual love affairs were attempts to reassure herself, just as some people use drink or mirrors. I'd always had a weak spot for her, no matter how exasperating she was. She was shallow, but she was spontaneously generous. I'd find it easy to fall in love with her but I was determined not to. She smiled demurely, and then looked out of the window. The River Thames was high, the water gleaming like oil. Against the current, a string of barges, piled high with rubbish, moved very slowly and were devoured piecemeal by an arch of Waterloo Bridge.

'I'll let you, Tessa. I can use any help I can get.'

'I phoned your mother. She worries about you.'

'Mothers always worry,' I said.

'She said the children are coming back to Duke Street. Nanny is still with them, that's one good thing. She's been wonderful, that girl. I didn't think she had it in her. It's probably very uncomfortable for her, cramped up in that little house of your mother's. Anyway I thought I'd come over to Duke Street with my cleaning woman and get everything ready for them. Okay?'

'It's nice of you, Tessa. But I'm sure it will be all right.'

'That's because you're a man and you've got no idea of what has to be done in a house when two young children are moving in. They'll need the rooms aired, clean clothes ready, beds made, food prepared, groceries in the cupboard and some cooked meals in the freezer.'

'I suppose you're right,' I said.

'Well, of course I'm right, darling. You don't think all these things get done by magic, do you?'

'I've got Mrs Dias,' I explained.

'Mrs Dias,' said Tessa. She laughed, drank some champagne, eyed the waiter and pointed to our glasses to get more. Then she laughed again at the thought of Mrs Dias. 'Mrs Dias, darling, is about as much use as a spare whatnot at a wedding, if you know what I mean.'

'I know what you mean,' I said. 'But Fiona always managed with Mrs Dias.'

'Because Fiona always did half the housework herself.'

'Did she? I didn't know that.'

'Of course you didn't. Men don't know anything. But the fact remains that you'll have to get the house properly organized if you are to hang on to your children. It won't be easy, Bernard. But I'll do everything I can.'

'It's very kind of you, Tessa.'

'I'm determined that David won't get his hands on them.' The waiter brought the food. Tessa held up her glass and said, 'Good luck, Bernard.' Leaning across the table to me, she said, 'Champagne – real French champagne – is not fattening. I'm going to this perfectly wonderful doctor who's put me on a diet.'

'I'm glad to hear the wonderful news about champagne,' I said. 'How fattening is cheap red Spanish plonk?'

'Don't start all that working-class-boy-makes-good stuff. I've heard it all before. Now let's get this straight; I'll send a car to bring your nanny and the children from your mother's house on Saturday morning. George can always find a car from one of the showrooms, and a spare driver.'

'Thanks,' I said. 'Was there something else you wanted to talk to me about?'

'No, no, no,' she said. 'Just about the house. I'll get it in some sort of order. Give me your door key. I know you keep a spare one in your office desk.'

'Is there anything you don't know?' I said.

She looked up and reached across the table to touch the back of my hand with her outstretched finger. Her touch made me shiver. 'Quite a lot of things I don't know, Bernard.' she said. 'But all in good time, eh?'

Werner did not arrive at three o'clock. He did not get Dicky's message until after lunch. The plane on which he was due to fly out of Berlin-Tegel had some mechanical malfunction. Since the old agreements specify that German airliners may not use the airlanes between Berlin and West Germany, there was a delay while another British Airways plane was brought into service. When eventually the plane did arrive in London, Werner was not aboard.

Werner did not arrive the following day. I phoned his apartment in Berlin-Dahlem but the phone was unanswered.

By the third day Dicky was uttering threats and dark suspicions. 'But the Berlin office sent a car,' said Dicky plaintively. 'And arranged his air ticket, and had one hundred pounds in sterling left with the driver. Where the hell has the bloody man gone?'

'There's probably a good explanation,' I said.

'It had better be a bloody show-stopper,' said Dicky. 'Now even the Deputy D-G has started asking about Stinnes. What am I supposed to say? Tell me that, will you?' It was not a rhetorical question; he stared at me and waited for an answer. When none came he pulled out his handkerchief and dabbed his eyes. He stood for a moment, breathing deeply as if preparing to sneeze, and then finally blew his nose. 'I still haven't shaken off that cold,' he said.

'A couple of days at home might be the best way of curing it,' I said.

He shot me a suspicious glance and then said, 'It might come to that. I'm beginning to think I might be infectious.'

'Give Werner until the weekend,' I said. 'Then perhaps we should put out some sort of alert or a contact string to find out where he is.'

'Did you phone Frank Harrington?'