Now there was no indecision about her, she knew what she must do and that it must be done quickly. She rang for Yvette and changed into the evening gown of white lace. Then she ran down the corridor into the drawing room where the Grand Duke would be waiting before dinner.

He looked up as she entered. Then, as he saw her face, he rose to his feet.

‘Father, something has happened! Please listen to me! I want to tell you all about it,’ Mistral said breathlessly.

Looking down at her, the Grand Duke knew that from this moment there would no longer be any secrets between them.

It was nearly two hours later that Sir Robert, sitting in an arm chair by the window of the sitting room in the Hôtel Hermitage, heard a knock on the door.

The windows were open and he was looking out on to the dusky night. A new moon was rising over the sea, the evening stars were coming out one after another. He did not turn his head at the interruption, thinking it was a servant coming to replenish the fire or to bring him a drink.

He went on looking out into the darkness. He heard someone enter and the door close. Then there was silence. Still he did not move until some sixth sense told him that he was being watched, that someone was standing looking at him. Impatiently he turned his head and the words he was about to say died on his lips, for it was Mistral who stood there.

For a moment he thought that she must be a figment of his own imagination. The light from the chandelier illuminated her very clearly and never, he thought, had he seen her look more lovely. Her dress was white and somehow it made her seem younger and more appealing, and yet it may have been the expression on her face, her eyes very wide and dark against the pale gold of her shining hair.

As he stared, unable for a moment to move or speak, Mistral with a swift movement slipped down on her knees beside him, her little hands clasped together on the arms of his chair.

‘I have come to say something to you,’ she said and her voice was very low and sweet. ‘You asked me to swear to you on my knees, by all that I held holy, that I did not know that my aunt was Madame Bleuet. I did know that she had been called Madame Bleuet, but – until she died I did not know who she was or how – notorious she had become under that name. I had no idea of anything – she did or of – the – wickedness with which she was connected. This I swear to you now – before God and by – all His Holy Saints.’