With an ejaculation he handed it to his wife. Then he glanced at my friend.

‘Just a minute, Monsieur Poirot, I feel you ought to know about this. It’s from Hoffberg. He thinks he’s found a customer for the diamond – an American, sailing for the States tomorrow. They’re sending down a chap tonight to vet the stone. By Jove, though, if this goes through –’ Words failed him.

Lady Yardly had turned away. She still held the telegram in her hand.

‘I wish you wouldn’t sell it, George,’ she said, in a low voice. ‘It’s been in the family so long.’ She waited, as though for a reply, but when none came her face hardened. She shrugged her shoulders. ‘I must go and dress. I suppose I had better display “the goods”.’ She turned to Poirot with a slight grimace. ‘It’s one of the most hideous necklaces that was ever designed! George has always promised to have the stones reset for me, but it’s never been done.’ She left the room.

Half an hour later, we three were assembled in the great drawing-room awaiting the lady. It was already a few minutes past the dinner hour.

Suddenly there was a low rustle, and Lady Yardly appeared framed in the doorway, a radiant figure in a long white shimmering dress. Round the column of her neck was a rivulet of fire. She stood there with one hand just touching the necklace.

‘Behold the sacrifice,’ she said gaily. Her ill-humour seemed to have vanished. ‘Wait while I turn the big light on and you shall feast your eyes on the ugliest necklace in England.’

The switches were just outside the door. As she stretched out her hand to them, the incredible thing happened. Suddenly, without any warning, every light was extinguished, the door banged, and from the other side of it came a long-drawn piercing woman’s scream.

‘My God!’ cried Lord Yardly. ‘That was Maude’s voice! What has happened?’

We rushed blindly for the door, cannoning into each other in the darkness. It was some minutes before we could find it. What a sight met our eyes! Lady Yardly lay senseless on the marble floor, a crimson mark on her white throat where the necklace had been wrenched from her neck.

As we bent over her, uncertain for the moment whether she was dead or alive, her eyelids opened.

‘The Chinaman,’ she whispered painfully. ‘The Chinaman – the side door.’

Lord Yardly sprang up with an oath. I accompanied him, my heart beating wildly. The Chinaman again! The side door in question was a small one in the angle of the wall, not more than a dozen yards from the scene of the tragedy. As we reached it, I gave a cry. There, just short of the threshold, lay the glittering necklace, evidently dropped by the thief in the panic of his flight. I swooped joyously down on it. Then I uttered another cry which Lord Yardly echoed. For in the middle of the necklace was a great gap. The Star of the East was missing!