Again the first line of defence, a rather flimsy one, had been broken through. The second line was instantly unveiled.

“I have been robbed, then, that is what you mean? Some wretch has stolen the drug and filled up the bottle again to deceive me.”

“It looks like that, certainly.” Could I believe that this was Tarleton speaking? His voice remained perfectly steady as he went on. “Unfortunately, one of the Club servants, named Gerard, has told the police a different tale.”

All at once Madame Bonnell turned very white. She began breathing in spasms.

“His story is that you threw out hints to him that Dr. Weathered was in danger of being poisoned, as you pretended, by enemies of his in the Club. At a later time you bribed Gerard to say that the doctor himself was afraid, and had given him instructions to watch over his drinks. What really happened was that your continued hints made Gerard watchful, and on the fatal night he did see something dropped in the doctor’s cup by a dancer whom he described correctly. We know that it was a harmless dose of opium, a drug to which Weathered was immune, because he was taking it. Gerard reported what he had seen to you and you thereupon told him that it was what you had feared but that you had an antidote. You put this antidote, as you called it, into a fresh cup of coffee, and made him take it to the doctor. There is no doubt in my mind that he died in consequence of drinking it.”

Madame Bonnell’s perfect composure was gone. That angry spark had come back into her eyes to remain there. She clenched her teeth, and her words came through them like the click of castanets.

“Gerard is a bloody liar.”

The next instant she recollected herself. She had still a third line of defence, a really good one this time.

“Are you going to tell that story to the world? Aha! I can tell stories, too. I shall have a fine tale to tell about His Royal Highness the Crown Prince of Slavonia; yes, yes. I shall tell how His Highness came to dance with poisoners and prostitutes, and people whose minds were fouler than any sink; and saw a murder committed under his eyes by his partner in the dance. Is it not so? And I shall recite much from all those letters I have read. I have a good memory, and I recite well.”

Tarleton acknowledged the strength of this position.