‘There,’ he said, turning to show his discovery to Leclerc and Gabrielle. He tapped his finger on the page. ‘That’s the man who attacked me.’

It was the illustration for the emotion of terror – an old man, his eyes wide, his toothless mouth agape. Electric calipers were being applied to his facial muscles by the great French doctor Duchenne, an expert in galvanism, in order to stimulate the required expression.

Hoffmann could sense the others’ scepticism – no, worse: their dismay.

‘I’m sorry,’ said Leclerc, puzzled. ‘You’re telling us that this is the man who was in your house tonight?’

‘Oh, Alex,’ said Gabrielle.

‘Obviously I’m not saying it’s literally him – he’s been dead more than a century – I’m saying it looks like him.’ They were both staring at him intently. They believe I have gone mad, he thought. He took a breath. ‘Okay. Now this book,’ he explained carefully to Leclerc, ‘arrived yesterday without any explanation. I didn’t order it, right? I don’t know who sent it. Maybe it’s a coincidence. But you’ve got to agree it’s odd that a few hours after this arrives, a man – who actually looks as though he’s just stepped out of its pages – turns up to attack us.’ They were silent. ‘Anyway,’ he concluded, ‘all I’m saying is, if you want to make an artist’s impression of the guy, you should start with this.’

‘Thank you,’ said Leclerc. ‘I’ll bear that in mind.’

There was a pause.

‘Right,’ said Gabrielle brightly. ‘Let’s get you to the hospital.’

Leclerc saw them off from the front door.

The moon had disappeared behind the clouds.