"The Countess," Passmore continued, "shortly afterwards visited these rooms. An hour after her departure Duson was dead. He died from drinking out of your liqueur glass, into which a few specks of that powder, invisible almost to the naked eye, had been dropped.
At Dorset House Reginald Brott was waiting for her. He left shortly afterwards in a state of agitation."
"And from these things," Mr. Sabin said, "you draw, I presume, the natural inference that Madame la Duchesse, desiring to marry her old admirer, Reginald Brott, first left me in America, and then, since I followed her here, attempted to poison me "There is," Passmore said, "a good deal of evidence to that effect."
"Here," Mr. Sabin said, handing him Duson's letter, "is some evidence to the contrary."
Passmore read the letter carefully.
"You believe this," he asked, "to be genuine?"
Mr. Sabin smiled.
"I am sure of it!" he answered.
"You recognise the handwriting?"
"Certainly!"
"And this came into your possession - how?"
"I found it on the table by Duson's side."
"You intend to produce it at the inquest?"
"I think not," Mr. Sabin answered.
There was a short silence. Passmore was revolving a certain matter in his mind - thinking hard. Mr. Sabin was apparently trying to make rings of the blue smoke from his cigarette.
"Has it occurred to you," Passmore asked, "to wonder for what reason your wife visited these rooms on the morning of Duson's death?"
Mr. Sabin shook his head.
"I cannot say that it has."
"She knew that you were not here," Passmore continued. "She left no message. She came closely veiled and departed unrecognised."
Mr. Sabin nodded.
"There were reasons," he said, "for that. But when you say that she left no message you are mistaken."
Passmore nodded.
"Go on," he said.
Mr. Sabin nodded towards a great vase of La France roses upon a side table.
"I found these here on my return," he said, "and attached to them the card which I believe is still there. Go and look at it."
Passmore rose and bent over the fragrant blossoms. The card still remained, and on the back of it, in a delicate feminine handwriting:
"For my husband, "with love from "Lucille."
Mr. Passmore shrugged his shoulders. He had not the vice of obstinacy, and he knew when to abandon a theory.
"I am corrected," he said. "In any case, a mystery remains as well worth solving. Who are these people at whose instigation Duson was to have murdered you - these people whom Duson feared so much that suicide was his only alternative to obeying their behests?"
Mr. Sabin smiled faintly.
"Ah, my dear Passmore," he said, "you must not ask me that question.
I can only answer you in this way. If you wish to make the biggest sensation which has ever been created in the criminal world, to render yourself immortal, and your fame imperishable - find out! I may not help you, I doubt whether you will find any to help you. But if you want excitement, the excitement of a dangerous chase after a tremendous quarry, take your life in your hands, go in and win.
Passmore's withered little face lit up with a gleam of rare excitement.
"These are your enemies, sir," he said. "They have attempted your life once, they may do it again. Assume the offensive yourself.
Give me a hint."
Mr. Sabin shook his head.
"That I cannot do," he said. "I have saved you from wasting your time on a false scent. I have given you something definite to work upon. Further than that I can do nothing."
Passmore looked his disappointment, but he knew Mr. Sabin better than to argue the matter.
"You will not even produce that letter at the inquest?" he asked.
"Not even that," Mr. Sabin answered.
Passmore rose to his feet.
"You must remember," he said, "that supposing any one else stumbles upon the same trail as I have been pursuing, and suspicion is afterwards directed towards madame, your not producing that letter at the inquest will make it useless as evidence in her favour."
"I have considered all these things," Mr. Sabin said. "I shall deposit the letter in a safe place. But its use will never be necessary. You are the only man who might have forced me to produce it, and you know the truth."
Passmore rose reluctantly.
"I want you," Mr. Sabin said, "to leave me not only your address, but the means of finding you at any moment during the next four-and-twenty hours. I may have some important work for you."
The man smiled as he tore leaf from his pocketbook and a made a few notes.
"I shall be glad to take any commission from you, sir," he said.
"To tell you the truth, I scarcely thought that you would be content to sit down and wait."
Mr. Sabin smiled.
"I think," he said, "that very shortly I can find you plenty to do."
