"No," said Larose quickly, "I don't imagine it, sir. It was never apparent until after last Tuesday night, but still that is no concrete evidence, I admit. However, there are other things." He leant over towards the Commissioner and lowered his voice. "For two nights now, at intervals someone has been coughing somewhere in Van Steyne's house, and whoever it is makes desperate efforts to strangle the cough." He emphasised his point with upraised hand. "Now, you remember what the accountant at the Rialto told us about Fallon's cough?"
"But where does the cough come from?" asked the Commissioner. "It may be one of the maids."
"No, it is a man's cough," said the detective emphatically. "I am sure of that." He paused considering. "But where it comes from I am never certain. Sometimes it seems
