“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.