"That is true," said the doctor. "Look!" and he took up from the floor by his knee the weapon which had caused Marthe Gobin's death. It was nothing but an ordinary skewer with a ring at one end and a sharp point at the other, and a piece of common white firewood for a handle. The wood had been split, the ring inserted and spliced in position with strong twine. It was a rough enough weapon, but an effective one. The proof of its effectiveness lay stretched upon the floor beside them.

Hanaud gave it to the manager of the hotel.

"You must be very careful of this, and give it as it is to the police."

Then he bent once more over Marthe Gobin.

"Did she suffer?" he asked in a low voice.

"No; death must have been instantaneous," said the doctor.

"I am glad of that," said Hanaud, as he rose again to his feet.

In the doorway the driver of the cab was standing.

"What has he to say?" Hanaud asked.

The man stepped forward instantly. He was an old, red-faced, stout man, with a shiny white tall hat, like a thousand drivers of cabs.

"What have I to say, monsieur?" he grumbled in a husky voice. "I take up the poor woman at the station and I drive her where she bids me, and I find her dead, and my day is lost. Who will pay my fare, monsieur?"

"I will," said Hanaud. "There it is," and he handed the man a five-franc piece. "Now, answer me! Do you tell me that this woman was murdered in your cab and that you knew nothing about it?"

"But what should I know? I take her up at the station, and all the way up the hill her head is every moment out of the window, crying, 'Faster, faster!' Oh, the good woman was in a hurry! But for me I take no notice. The more she shouts, the less I hear; I bury my head between my shoulders, and I look ahead of me and I take no notice. One cannot expect cab-horses to run up these hills; it is not reasonable."

"So you went at a walk," said Hanaud. He beckoned to Ricardo, and said to the manager: "M. Besnard will, no doubt, be here in a few minutes, and he will send for the Juge d'Instruction. There is nothing that we can do."

He went back to Ricardo's sitting-room and flung himself into a chair.

He had been calm enough downstairs in the presence of the doctor and the body of the victim. Now, with only Ricardo for a witness, he gave way to distress.

"It is terrible," he said. "The poor woman! It was I who brought her to Aix. It was through my carelessness. But who would have thought--?" He s.n.a.t.c.hed his hands from his face and stood up. "I should have thought,"

he said solemnly. "Extraordinary daring--that was one of the qualities of my criminal. I knew it, and I disregarded it. Now we have a second crime."

"The skewer may lead you to the criminal," said Mr. Ricardo.

"The skewer!" cried Hanaud. "How will that help us? A knife, yes--perhaps. But a skewer!"

"At the shops--there will not be so many in Aix at which you can buy skewers--they may remember to whom they sold one within the last day or so."

"How do we know it was bought in the last day or so?" cried Hanaud scornfully. "We have not to do with a man who walks into a shop and buys a single skewer to commit a murder with, and so hands himself over to the police. How often must I say it!"

The violence of his contempt nettled Ricardo.

"If the murderer did not buy it, how did he obtain it?" he asked obstinately.

"Oh, my friend, could he not have stolen it? From this or from any hotel in Aix? Would the loss of a skewer be noticed, do you think? How many people in Aix to-day have had rognons a la brochette for their luncheon! Besides, it is not merely the death of this poor woman which troubles me. We have lost the evidence which she was going to bring to us. She had something to tell us about Celie Harland which now we shall never hear. We have to begin all over again, and I tell you we have not the time to begin all over again. No, we have not the time. Time will be lost, and we have no time to lose." He buried his face again in his hands and groaned aloud. His grief was so violent and so sincere that Ricardo, shocked as he was by the murder of Marthe Gobin, set himself to console him.

"But you could not have foreseen that at three o'clock in the afternoon at Aix--"

Hanaud brushed the excuse aside.

"It is no extenuation. I OUGHT to have foreseen. Oh, but I will have no pity now," he cried, and as he ended the words abruptly his face changed. He lifted a trembling forefinger and pointed. There came a sudden look of life into his dull and despairing eyes.

He was pointing to a side-table on which were piled Mr. Ricardo's letters.

"You have not opened them this morning?" he asked.

"No. You came while I was still in bed. I have not thought of them till now."

Hanaud crossed to the table, and, looking down at the letters, uttered a cry.

"There's one, the big envelope," he said, his voice shaking like his hand. "It has a Swiss stamp."

He swallowed to moisten his throat. Ricardo sprang across the room and tore open the envelope. There was a long letter enclosed in a handwriting unknown to him. He read aloud the first lines of the letter:

"I write what I saw and post it to-night, so that no one may be before me with the news. I will come over to-morrow for the money."

A low exclamation from Hanaud interrupted the words.

"The signature! Quick!"

Ricardo turned to the end of the letter.

"Marthe Gobin."

"She speaks, then! After all she speaks!" Hanaud whispered in a voice of awe. He ran to the door of the room, opened it suddenly, and, shutting it again, locked it. "Quick! We cannot bring that poor woman back to life; but we may still--" He did not finish his sentence. He took the letter unceremoniously from Ricardo's hand and seated himself at the table. Over his shoulder Mr. Ricardo, too, read Marthe Gobin's letter.

It was just the sort of letter, which in Ricardo's view, Marthe Gobin would have written--a long, straggling letter which never kept to the point, which exasperated them one moment by its folly and fired them to excitement the next.

It was dated from a small suburb of Geneva, on the western side of the lake, and it ran as follows:

"The suburb is but a street close to the lake-side, and a tram runs into the city. It is quite respectable, you understand, monsieur, with a hotel at the end of it, and really some very good houses. But I do not wish to deceive you about the social position of myself or my husband. Our house is on the wrong side of the street--definitely--yes.

It is a small house, and we do not see the water from any of the windows because of the better houses opposite. M. Gobin, my husband, who was a clerk in one of the great banks in Geneva, broke down in health in the spring, and for the last three months has been compelled to keep indoors. Of course, money has not been plentiful, and I could not afford a nurse. Consequently I myself have been compelled to nurse him. Monsieur, if you were a woman, you would know what men are when they are ill--how fretful, how difficult. There is not much distraction for the woman who nurses them. So, as I am in the house most of the day, I find what amus.e.m.e.nt I can in watching the doings of my neighbours. You will not blame me.

"A month ago the house almost directly opposite to us was taken furnished for the summer by a Mme. Rossignol. She is a widow, but during the last fortnight a young gentleman has come several times in the afternoon to see her, and it is said in the street that he is going to marry her. But I cannot believe it myself. Monsieur is a young man of perhaps thirty, with smooth, black hair. He wears a moustache, a little black moustache, and is altogether captivating. Mme. Rossignol is five or six years older, I should think--a tall woman, with red hair and a bold sort of coa.r.s.e beauty. I was not attracted by her. She seemed not quite of the same world as that charming monsieur who was said to be going to marry her. No; I was not attracted by Adele Rossignol."

And when he had come to that point Hanaud looked up with a start.

"So the name was Adele," he whispered.

"Yes," said Ricardo. "Helene Vauquier spoke the truth."

Hanaud nodded with a queer smile upon his lips.

"Yes, there she spoke the truth. I thought she did."

"But she said Adele's hair was black," interposed Mr. Ricardo.

"Yes, there she didn't," said Hanaud drily, and his eyes dropped again to the paper.