“Frankly, then, madam, I do not.”

“You think that he is dead?”

“I do.”

“Murdered?”

“I don’t say that. Perhaps.”

“And on what day did he meet his death?”

“On Monday.”

“Then perhaps, Mr. Holmes, you will be good enough to explain how it is that I have received a letter from him today.”

Sherlock Holmes sprang out of his chair as if he had been galvanised.

“What!” he roared.