Before Betty could reply there came a knock upon the door.
"Come in," Hanaud cried out, and a small, dark, alert man in plain clothes entered the room.
"This is Nicolas Moreau, who was keeping watch in the courtyard. I sent him some while ago upon an errand," he explained and turned again to Moreau.
"Well, Nicolas?"
Nicolas stood at attention, with his hands at the seams of his trousers, in spite of his plain clothes, and he recited rather than spoke in a perfectly expressionless official voice.
"In accordance with instructions I went to the shop of Jean Cladel. It is number seven. From the Rue Gambetta I went to the Prefecture. I verified your statement. Jean Cladel has twice appeared before the Police Correctionelle for selling forbidden drugs and has twice been acquitted owing to the absence of necessary witnesses."
"Thank you, Nicolas."
Moreau saluted, turned on his heel, and went out of the room. There followed a moment of silence, of discouragement. Hanaud looked ruefully at Betty.
"You see! I must go on. We must search in that locked cabinet of Simon Harlowe's for the poison arrow, if by chance it should be there."
"The room is sealed," Frobisher reminded him.