To do the lady justice, Miss Spencer bore the surprising ordeal very well.

She did not flinch; she betrayed no emotion. The sole sign of perturbation was in her hurried breathing.

‘You have ceased to be the Baroness Zerlinski,’ Nella continued. ‘May I sit down?’

‘Certainly, sit down,’ said Miss Spencer, copying the girl’s tone. ‘You are a fairly smart young woman, that I will say. What do you want? Weren’t my books all straight?’

‘Your books were all straight. I haven’t come about your books. I have come about the murder of Reginald Dimmock, the disappearance of his corpse, and the disappearance of Prince Eugen of Posen. I thought you might be able to help me in some investigations which I am making.’

Miss Spencer’s eyes gleamed, and she stood up and moved swiftly to the mantelpiece.

‘You may be a Yankee, but you’re a fool,’ she said.

She took hold of the bell-rope.

‘Don’t ring that bell if you value your life,’ said Nella.

‘If what?’ Miss Spencer remarked.