Sanders stared at her in his rear-view mirror but kept his thoughts on her politics to himself.

‘What about Harry?’ asked Jilly. ‘What else do you know about her?’

‘We don’t know much,’ Sanders admitted. ‘But there was plenty of speculation at the time. Fifteen years ago, a brigadier general’s unruly daughter went missing in Germany. She left a note saying she was running away. She was fifteen, rebellious. A lot of anarchist literature was found in her bedroom.’

‘And her name was Harriet?’ Jilly suggested.

‘No,’ said Sanders. ‘Her name wasn’t Harriet. But her mother’s name had been. Her mother was dead. The story went that the general used to get roaring drunk and hit his wife, made her life hell. She committed suicide when the daughter was eight or nine.’

‘Well, well,’ said Hepton, very quietly, filing this information away.

Hyde Park Corner came next, and then they were sweeping into Park Lane itself. Sanders entered the right-hand-turning lane and cut across the oncoming traffic, bringing the car to a stop outside a flat-fronted hotel of marble and smoked glass, which seemed very similar to the other hotels clustered around it. Three steps led to a line of six glass doors, behind which lay tantalising glances of a marble reception hall lit by sparkling chandeliers. In front of the steps stood a liveried doorman, and above him was a large canopy proclaiming the single word Achilles.

Sanders got out of the car and locked his door. When Hepton closed his own door, he watched the button on the inside of the window slide neatly into place of its own accord.

‘A wonderful thing, central locking,’ he mused.

Jilly was staring at the hotel’s frontage. ‘The things I’d do for a long, hot bath,’ she said.

The doorman was coming towards them. ‘You can’t leave it there, sir,’ he called, gesturing towards the Cavalier.

Sanders reached into his inside pocket and brought out a wallet, which he flipped open.

‘A security matter,’ he said. ‘We shouldn’t be too long.’

The doorman studied the ID carefully. ‘Well,’ he said at last, ‘I suppose that’ll be all right then. Want the manager, do you?’

‘That’s quite all right.’ Sanders beamed back at him. ‘We’ll manage.’ He moved past the doorman and up the steps.

‘I thought he was supposed to be our bodyguard?’ Jilly whispered as they followed, leaving the bemused doorman staring at their backs.

‘He is.’

‘Well he’s not doing a very good job then, is he?’

‘He’s a bit too keen on playing the spy,’ Hepton agreed. ‘We can’t afford to relax, Jilly. I think we’re going to have to cover our own backs, rather than depending on Mr Sanders to do it for us.’

‘Well, as long as we’ve got the kitchen knife, we should be safe,’ said Jilly.