‘The curse has struck,’ he said and it took Norah a moment to realise that he wasn’t speaking to her, but to someone behind her.

She wheeled round and saw Theresa holding a video camera.

‘What the fuck’s going on?’ Norah asked.

The hulking man with the quick, cold eyes that looked too small for his face tossed his top hat onto the ground and smiled.

‘My dear Miss Richter,’ he said, ‘have you still not worked it out?’

Norah stared at him mutely. She hadn’t seen Balder since their last meeting in Berlin and had forgotten how intimidating he was with his massive form and sinister smile.

‘Art,’ Balder said soberly. And then, smiling, ‘Raw, real, bloody, sweaty, filthy, grim, throbbing art.’

Norah took another step backwards.

‘I don’t understand.’

That shark’s rictus again.

‘I think it’s only fair that I explain it to you,’ said Balder.

Norah glanced at Theresa. Balder noticed.

‘Yes,’ he said. ‘She’s one of mine.’

Theresa stared at the ground. Norah was about to say something, but didn’t have a chance.

‘Curse,’ Balder cried, ‘is my last great work of art.’

‘Curse?’ Norah asked.

The professor nodded.

‘On February 11 you will kill a man called Arthur Grimm,’ he said dramatically. ‘With good reason and of your own free will.’

‘How do you know what the woman said?’ Norah asked.

Balder bared his teeth.

‘Because I paid her to say it.’

He studied Norah’s face, evidently satisfied with what he saw.

‘But why?’ she asked.

Balder tilted his head, as if waiting patiently for her to work it out for herself.

‘Art,’ Norah said dully.

‘An experiment,’ Balder explained.

‘But…Valerie…’ Norah stammered.

He tilted his head again.

‘Do you know what a self-fulfilling prophecy is?’ he asked.

Norah stared at him in silence.

‘Forgive me,’ he said. ‘Of course you do. It’s not hard, after all. A fortune teller prophesies to a superstitious woman that a tall, dark stranger will soon appear in her life and, unconsciously, that woman does everything to fulfil the prophecy. Her world is suddenly full of tall, dark men; she begins actively to seek their company. Looking back, the prophecy will seem to her confirmed, but in fact, she herself has done all the work.’

Norah still said nothing.

‘Curse was based on the same principle. As I said, it was an experiment. What happens if we prophesy something completely absurd to someone sane, intelligent and not remotely superstitious? Will it be fulfilled?’

‘You wanted me to kill Grimm?’ Norah said.

She could hear her voice trembling.

‘No, you’ve got it all wrong,’ said Balder, clutching his chest in a dramatic gesture of innocence. ‘I never wanted you to kill him, young lady; it was an experiment. Did Jackson Pollock know how his pictures would turn out before he threw the paint at the canvases? All I wanted was to see what would happen. I had no idea how it would turn out. There were thousands of possible outcomes. You might have ignored the whole thing, gone to the police, lain low, gone on holiday, moved to another city. Every step that has brought you here this evening was a conscious decision on your part. You decided to seek out Grimm. You decided you had a reason to kill him. And you killed him. All I did was to plant the words in your head: On February 11 you will kill a man called Arthur Grimm in the Prater, with good reason and of your own free will.’