man in plain clothes, who had been waiting upon the
landing, stepped forward. He carried in his hand a piece of thin,
strong whipcord.

"Ah, Durette!" cried Besnard. "Monsieur Hanaud, I sent Durette this
morning round the shops of Aix with the cord which was found knotted
round Mme. Dauvray's neck."

Hanaud advanced quickly to the man.

"Well! Did you discover anything?"

"Yes, monsieur," said Durette. "At the shop of M. Corval, in the Rue du
Casino, a young lady in a dark-grey frock and hat bought some cord of
this kind at a few minutes after nine last night. It was just as the
shop was being closed. I showed Corval the photograph of Celie Harland
which M. le Commissaire gave me out of Mme. Dauvray's room, and he
identified it as the portrait of the girl who had bought the cord."

Complete silence followed upon Durette's words. The whole party stood
like men stupefied. No one looked towards Wethermill; even Hanaud
averted his eyes.

"Yes, that is very important," he said awkwardly. He turned away and,
followed by the others, went up the stairs to the bedroom of Helene
Vauquier.

CHAPTER VI

HELENE VAUQUIER'S EVIDENCE

A nurse opened the door. Within the room Helene Vauquier was leaning
back in a chair. She looked ill, and her face was very white. On the
appearance of Hanaud, the Commissaire, and the others, however, she
rose to her feet. Ricardo recognised the justice of Hanaud's
description. She stood before them a hard-featured, tall woman of
thirty-five or forty, in a neat black stuff dress, strong with the
strength of a peasant, respectable, reliable. She looked what she had
been, the confidential maid of an elderly woman. On her face there was
now an aspect of eager appeal.

"Oh, monsieur!" she began, "let me go from here--anywhere--into prison
if you like. But to stay here--where in years past we were so
happy--and with madame lying in the room below. No, it is
insupportable."

She sank into her chair, and Hanaud came over to her side.

"Yes, yes," he said, in a soothing voice. "I can understand your
feelings, my poor woman. We will not keep you here. You have, perhaps,
friends in Aix with whom you could stay?"

"Oh yes, monsieur!" Helene cried gratefully. "Oh, but I thank you! That
I should have to sleep here tonight! Oh, how the fear of that has
frightened me!"

"You need have had no such fear. After all, we are not the visitors of
last night," said Hanaud, drawing a chair close to h