Hanaud laughed immoderately at his joke. He alone seemed to feel no disappointment at Perrichet's oversight. Ricardo was a little touchy on the subject of his personal appearance, and bridled visibly. Hanaud turned towards Servettaz. "Now," he said, "you know how much petrol was taken from the garage?" "Yes, monsieur." "Can you tell me, by the amount which has been used, how far that car was driven last night?" Hanaud asked. Servettaz examined the tank. "A long way, monsieur. From a hundred and thirty to a hundred and fifty kilometres, I should say." "Yes, just about that distance, I should say," cried Hanaud. His eyes brightened, and a smile, a rather fierce smile, came to his lips. He opened the door, and examined with a minute scrutiny the floor of the carriage, and as he looked, the smile faded from his face. Perplexity returned to it. He took the cushions, looked them over and shook them out. "I see no sign--" he began, and then he uttered a little shrill cry of satisfaction. From the crack of the door by the hinge he picked off a tiny piece of pale green stuff, which he spread out upon the back of his hand. "Tell me, what is this?" he said to Ricardo. "It is a green fabric," said Ricardo very wisely. "It is green chiffon," said Hanaud. "And the frock in which Mlle. Celie went away was of green chiffon over satin. Yes, Mlle. Celie travelled in this car." He hurried to the driver's seat. Upon the floor there was some dark mould. Hanaud cleaned it off with his knife and held some of it in the palm of his hand. He turned to Servettaz. "You drove the car on Tuesday morning before you went to Chambery?" "Yes, monsieur." "Where did you take up Mme. Dauvray and Mlle. Celie?" "At the front door of the Villa Rose." "Did you get down from the seat at all?" "No, monsieur; not after I left the garage." Hanaud returned to his companions. "See!" And he opened his hand. "This is black soil--moist from last night's rain--soil like the soil in front of Mme. Dauvray's salon. Look, here is even a blade or two of the grass"; and he turned the mould over in the palm of his hand. Then he took an empty envelope from his pocket and poured the soil into it and gummed the flap down. He stood and frowned at the motor-car. "Listen," he said, "how I am puzzled! There was a man last night at the Villa Rose. There were a man's blurred footmarks in the mould before the glass door. That man drove madame's car for a hundred and fifty kilometres, and he leaves the mould which clung to his boots upon the floor of his seat. Mlle. Celie and another woman drove away inside the car. Mlle. Celie leaves a fragment of the chiffon tunic of her frock which caught in the hinge. But Mlle. Celie made much clearer impressions in the mould than the man. Yet on the floor of the carriage there is no trace of her shoes. Again I say there is something here which I do not understand." And he spread out his hands with an impulsive gesture of despair.