"But you saw the driver!" exclaimed Wethermill.

"Yes; what was he like?" cried the Commissaire.

Perrichet shook his head mournfully.

"He wore a talc mask over the upper part of his face, and had a little black moustache, and was dressed in a heavy great-coat of blue with a white collar."

"That is my coat, monsieur," said Servettaz, and as he spoke he lifted it up from the chauffeur's seat. "It is Mme. Dauvray's livery."

Harry Wethermill groaned aloud.

"We have lost him. He was within our grasp--he, the murderer!--and he was allowed to go!"

Perrichet's grief was pitiable.

"Monsieur," he pleaded, "a car slackens its speed and goes on again--it is not so unusual a thing. I did not know the number of Mme. Dauvray's car. I did not even know that it had disappeared"; and suddenly tears of mortification filled his eyes. "But why do I make these excuses?" he cried. "It is better, M. Hanaud, that I go back to my uniform and stand at the street corner. I am as foolish as I look."

"Nonsense, my friend," said Hanaud, clapping the disconsolate man upon the shoulder. "You remembered the car and its number. That is something--and perhaps a great deal," he added gravely. "As for the talc mask and the black moustache, that is not much to help us, it is true." He looked at Ricardo's crestfallen face and smiled. "We might arrest our good friend M. Ricardo upon that evidence, but no one else that I know."

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 gra.s.s"; 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 gla.s.s 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.

"It looks as if they had been careful and he careless," said Mr.

Ricardo, with the air of a man solving a very difficult problem.

"What a mind!" cried Hanaud, now clasping his hands together in admiration. "How quick and how profound!"

There was at times something elephantinely elfish in M. Hanaud's demeanour, which left Mr. Ricardo at a loss. But he had come to notice that these undignified manifestations usually took place when Hanaud had reached a definite opinion upon some point which had perplexed him.

"Yet there is perhaps, another explanation," Hanaud continued. "For observe, M. Ricardo. We have other evidence to show that the careless one was Mlle. Celie. It was she who left her footsteps so plainly visible upon the gra.s.s, not the man. However, we will go back to M.

Wethermill's room at the Hotel Majestic and talk this matter over. We know something now. Yes, we know--what do we know, monsieur?" he asked, suddenly turning with a smile to Ricardo, and, as Ricardo paused: "Think it over while we walk down to M. Wethermill's apartment in the Hotel Majestic."

"We know that the murderer has escaped," replied Ricardo hotly.

"The murderer is not now the most important object of our search. He is very likely at Ma.r.s.eilles by now. We shall lay our hands on him, never fear," replied Hanaud, with a superb gesture of disdain. "But it was thoughtful of you to remind me of him. I might so easily have clean forgotten him, and then indeed my reputation would have suffered an eclipse." He made a low, ironical bow to Ricardo and walked quickly down the road.

"For a c.u.mbersome man he is extraordinarily active," said Mr. Ricardo to Harry Wethermill, trying to laugh, without much success. "A heavy, clever, middle-aged man, liable to become a little gutter-boy at a moment's notice."

Thus he described the great detective, and the description is quoted.

For it was Ricardo's best effort in the whole of this business.

The three men went straight to Harry Wethermill's apartment, which consisted of a sitting-room and a bedroom on the first floor. A balcony ran along outside. Hanaud stepped out on to it, looked about him, and returned.

"It is as well to know that we cannot be overheard," he said.

Harry Wethermill meanwhile had thrown himself into a chair. The mask he had worn had slipped from its fastenings for a moment. There was a look of infinite suffering upon his face. It was the face of a man tortured by misery to the snapping-point.

Hanaud, on the other hand, was particularly alert. The discovery of the motor-car had raised his spirits. He sat at the table.

"I will tell you what we have learnt," he said, "and it is of importance. The three of them--the man, the woman with the red hair, and Mlle. Celie--all drove yesterday night to Geneva. That is only one thing we have learnt."

"Then you still cling to Geneva?" said Ricardo.

"More than ever," said Hanaud.

He turned in his chair towards Wethermill.