The unbuttoned neck of her thin silk shirt revealed an expanse of butterscotch skin stretched over her bony sternum, giving an unattractively knobbly effect; yet two full, firm breasts jutted from her narrow ribcage, as though they had been borrowed for the day from a fuller-figured friend. ‘We could have met somewhere more discreet,’ commented Strike.

‘No, it’s fine, because nobody here will know who you are. You don’t look anything like your father, do you? I met him at Elton’s last summer. Freddie knows him. D’you see much of Jonny?’

‘I’ve met him twice,’ said Strike.

‘Oh,’ said Tansy.

The monosyllable contained equal parts of surprise and disdain.

Charlotte had had friends like this; sleek-haired, expensively educated and clothed, all of them appalled by her strange yen for the enormous, battered-looking Strike. He had come up against them for years, by phone and in person, with their clipped vowels and their stockbroker husbands, and the brittle toughness Charlotte had never been able to fake.

‘I don’t think she should be talking to you at all,’ said Ursula abruptly. Her tone and expression would have been appropriate had Strike been a waiter who had just thrown aside his apron and joined them, uninvited, at the table. ‘I think you’re making a big mistake, Tanz.’

Bristow said: ‘Ursula, Tansy simply—’

‘It’s up to me what I do,’ Tansy snapped at her sister, as though Bristow had not spoken, as though his chair was empty. ‘I’m only going to say what I heard, that’s all. It’s all off the record; John’s agreed to that.’

Evidently she too viewed Strike as domestic class. He was irked not only by their tone, but also by the fact that Bristow was giving witnesses assurances without his say-so. How could Tansy’s evidence, which could have come from nobody but her, be kept off the record?

For a few moments all four of them ran their eyes over the culinary options in silence. Ursula was the first to put down her menu. She had already finished a glass of wine. She helped herself to another, and glanced restlessly around the restaurant, her eyes lingering for a second on a blonde minor royal, before passing on.

‘This place used to be full of the most fabulous people, even at lunchtime. Cyprian only ever wants to go to bloody Wiltons, with all the other stiffs in suits…’

‘Is Cyprian your husband, Mrs May?’ asked Strike.

He guessed that it would needle her if he crossed what she evidently saw as an invisible line between them; she did not think that sitting at a table with her gave him a right to her conversation. She scowled, and Bristow rushed to fill the uncomfortable pause.

‘Yes, Ursula’s married to Cyprian May, one of our senior partners.’

‘So I’m getting the family discount on my divorce,’ said Tansy, with a slightly bitter smile.