‘On no account should you confront Anna Petrovna,’ Sandilands had told her. But how did you break off a discussion with a friendly girl on the relative merits of Lillywhites and Harrods when it came to buying hot-weather clothes? How did you leave in the middle of a laughing disagreement over the comparative virtues of cotton and celanese knickers? How did you make your excuses when your arm was being clutched in apparent friendship?

They leaned companionably over the waist-high parapet and decided that the current was flowing east.

‘There’s a tide running and it’s going out fast,’ remarked Anna, staring into the black water swirling fiercely around the piers. ‘It’s racing along with the current, you see. Anything falling into the water from here — if it survived being sucked down into that whirlpool — would be swept up and come ashore … um … round about there.’ She pointed. ‘The Savoy’s back garden. Let’s test our theory, shall we?’

Catching Lily completely by surprise, she tore the bag from Lily’s shoulder and threw it into the river. Lily squealed and turned on the taller girl, who had reapplied her hold on her right arm, squeezing until it was painful. The only way to attempt to break it was to smash upwards with the left fist at her face and stamp down on her instep at the same moment. Not a difficult manoeuvre. Lily had practised it on bigger and stronger targets. But it would be a desperate move and possibly a noisy one which she’d rather not attempt in a public place with people passing by. A punch in the face would get her out of trouble but she knew that the London bridges were patrolled by beat coppers. Sandilands would not be amused by a report that his plainclothes woman policeman had been arrested for an attack on a Russian aristocrat on Westminster Bridge.

‘Why did you do that? It was my grandfather’s bag. And very precious to me,’ she said, hoping to elicit a response she could understand.

‘Inherited goods mean nothing. They weigh one down. There it goes — the sweat, the screams, the bloodstains. The memories. It’s not popped back up again … it’s settling to rot on the river bed. Gone.’

‘I haven’t much of a past to let go,’ said Lily. ‘I can’t afford to be so cavalier with the little I have.’

‘Poor creature.’ There was no sympathy in the voice. ‘You are upset by the loss of a dirty old bag? I have lost the world. A country. A family. A fortune. A name. All I have left is my life and what is that to anyone? An embarrassment. An anachronism. Even a threat. I’ve become a danger to Aunt Tizzi and my own people. Time to move on.’ Her eyes were drawn in fascination again to the water. ‘They tell me this is the most popular spot in London for suicide. One sees why. How those dark depths call one to oblivion!’

She dropped Lily’s arm and edged a few paces further on to the bridge. She put her hands on the parapet, leaning dangerously forward to stare into the river.

Lily sidled after her. She recognized suicidal despair in the girl’s voice and at last realized why she’d been brought here. Many people killed themselves quietly, dying alone in holes and corners all over London, hugging their unbearable sorrows to their breast. But some — those who seemed to bear a grudge against society — preferred to go with a flourish, screaming out their hatred … or their guilt. Lily knew with a chilling certainty that she’d been chosen, lured on to the bridge, to hear the last words, to witness such a death.