‘“The Western Star”,’ finished Miss Marvell. ‘That’s so. At the time, Gregory remembers that there was some story attached to the stone, but the Chink wasn’t handing out any information. Gregory says he seemed just scared to death, and in a mortal hurry to get rid of the thing. He only asked about a tenth of its value. It was Greg’s wedding present to me.’

Poirot nodded thoughtfully.

‘The story seems of an almost unbelievable romanticism. And yet – who knows? I pray of you, Hastings, hand me my little almanac.’

I complied.

‘Voyons!’ said Poirot, turning the leaves. ‘When is the date of the full moon? Ah, Friday next. That is in three days’ time. Eh bien, madame, you seek my advice – I give it to you. This belle histoire may be a hoax – but it may not! Therefore I counsel you to place the diamond in my keeping until after Friday next. Then we can take what steps we please.’

A slight cloud passed over the actress’s face, and she replied constrainedly:

‘I’m afraid that’s impossible.’

‘You have it with you – hein?’ Poirot was watching her narrowly.

The girl hesitated a moment, then slipped her hand into the bosom of her gown, drawing out a long thin chain. She leaned forward, unclosing her hand. In the palm, a stone of white fire, exquisitely set in platinum, lay and winked at us solemnly.

Poirot drew in his breath with a long hiss.

‘Épatant!’ he murmured. ‘You permit, madame?’ He took the jewel in his own hand and scrutinized it keenly, then restored it to her with a little bow. ‘A magnificent stone – without a flaw. Ah, cent tonnerres! and you carry it about with you, comme ça!’

‘No, no, I’m very careful really, Monsieur Poirot. As a rule it’s locked up in my jewel-case, and left in the hotel safe deposit. We’re staying at the Magnificent, you know. I just brought it along today for you to see.’

‘And you will leave it with me, n’est-ce pas? You will be advised by Papa Poirot?’

‘Well, you see, it’s this way, Monsieur Poirot. On Friday we’re going down to Yardly Chase to spend a few days with Lord and Lady Yardly.’

Her words awoke a vague echo of remembrance in my mind. Some gossip – what was it now? A few years ago Lord and Lady Yardly had paid a visit to the States, rumour had it that his lordship had rather gone the pace out there with the assistance of some lady friends – but surely there was something more, more gossip which coupled Lady Yardly’s name with that of a ‘movie’ star in California – why! it came to me in a flash – of course it was none other than Gregory B. Rolf.

‘I’ll let you into a little secret, Monsieur Poirot,’ Miss Marvell was continuing. ‘We’ve got a deal on with Lord Yardly. There’s some chance of our arranging to film a play down there in his ancestral pile.’