"'De Quincey was right, and murder should be a fine art. But the Borgias--only amateurs! The far-famed Aqua Tofana--pooh! Any chemist will put it up for ten cents. Only be careful how you use it. Chemical analysis has advanced somewhat since the day of the divine Lucrezia, and a jury would convict without leaving their seats.' "'Rather rough on your business, I should think,' said Estes, speaking somewhat thickly, for the port had stopped with him overfrequently of late. 'Is poisoning really out of date?' he continued. "'As absolutely as crinoline and the novels of G. P. R. James,' answered our host, lightly. But I, who was watching him closely, saw his eyes harden. Estes had said more than one imprudent thing that evening, and this time he had gone too far. I would have to get the boy away somehow. "There were three of us dining with Balencourt that evening at his chambers in the Argyle--Estes, Crawfurd, and myself; and as usual we had had an excellent dinner, for Balencourt knew how to live. Who was Balencourt? Well, nobody could answer that precisely, but his letters of introduction had been unexceptionable and his checks were always honored at Brown Brothers. Moreover, Crawfurd had met him frequently at the Jockey Club in Paris, and there was his name on White's books for any one to read. A man of forty-five perhaps, clean-shaven, well set up, an inveterate globe-trotter, a prince among raconteurs, and the most astounding polyglot I have ever met. I myself have heard him talk Eskimo with one of Peary's natives, and he had collated some of his researches into Iranic-Turanian root-forms for the Philological Society. But let us go back to our walnuts. "Crawfurd picked up the thread. 'Then the science of assassination is a lost art,' he said, tentatively. "'Oh, I did not say that,' replied Balencourt, carelessly. 'There are other ways--better ones.' "'You mean beyond the risk of detection?' "'Perfectly.' "'Eliminating the toxic poisons of all kinds?' "'If you like.' "'I doubt it.' said Crawfurd, with a little hesitation. "'And I deny it,' interrupted Estes, rudely, and stared straight at Balencourt. A quick glance answered his challenge; it was like the engaging of rapiers. "'Perhaps Mr. Estes desires proof,' said Balencourt, slowly. "'I do.' "'Let us say between--' "'To-night and the 1st of August.' "'That will suit me perfectly. My passage is booked on the Teutoninc for the following Wednesday.' "'It is also the day set for my wedding to Miss Catherwood,' said Estes, quietly. "Balencourt took it admirably. 'So you have obtained the decision at last,' he said, smiling lightly. 'My felicitations.' "Crawfurd rose to his feet. The jovial flush had strained away from his fat cheeks, and his jaw hung loose and pendulous. 'For God's sake, fellows--' he began, but Balencourt stopped him with a gesture.