The clerk, who had admitted Juve, withdrew, and M. de Maufil, the amiable director, gave the police officer his most gracious smile.

"When I applied this morning at headquarters for an officer to be sent here, I scarcely expected to receive so celebrated a detective, upon a matter which is really very commonplace."

"Your letter to M. Havard mentioned a person I have been looking for with the greatest interest for the past two days. Loupart, alias 'The Square,'" replied Juve, "that is why I came myself. What is it about, sir?"

"Well, the day before yesterday, we took in at the instance of Doctor Patel, a patient suffering from acute gastric trouble. The woman gave us for identification the name of Josephine, no calling, residing in Paris, Rue de Goutte d'Or, in furnished rooms. Some hours after her admission to the hospital, she received a letter, brought by a messenger, which threw her into a violent state of terror. The nurse on duty sent for me, and I succeeded, after great difficulty, in quieting her; but she insisted most emphatically on leaving the hospital at once. The poor creature was in a high fever, and to grant her request would have been sending her to her death. At length she intrusted me with the letter which had excited her so. Here it is, kindly look it over."

Juve took the letter and read:

"Am just back from the doss. You ain't there, and I don't want any more of these dodges. You are no more ill than I am. See here, you'll either leave the hospital and slope back to the house right off or to-morrow, Friday, at visiting time, as sure as my name's what it is, you'll get two bullets in your hide to teach you to hold your tongue."

Juve gave a grunt of satisfaction.

"You understand what is going on?" asked the director.

"Yes, but please go on with your story."

"Well, sir, you can guess that having read this letter, I easily got from the girl some information as to the writer. According to what she told me this Loupart is her lover, and he seems to have in a high degree that inconceivable pride which causes folks of his class, when they have sworn to kill some one, to carry out their threat, no matter what risk they may run themselves. The girl, Josephine, is convinced that to-morrow Loupart will come and kill her."

"You have told her that all precautions will be taken?"

"Of course. I pointed out to her that people do not come in here as they do into a bar; that being warned, I should have all the visitors watched who come here and asked to see her. I repeated to her that her lover probably wanted to frighten her, but that he could not do anything to injure her. I insisted that in the state she was in it was physically impossible for her to obey that wretch's bidding."

"And what was her answer to that?"

"Nothing. Her attack of alarm having subsided she seemed to fall into a condition of extreme prostration. I realised quite well that she regarded herself as condemned, that she had a far higher opinion of Loupart's daring than of my watchfulness, and, lastly, if she stayed it was because she realised that it was out of the question for her, in her weak state, to go back to her home."

While the director was speaking, Juve had retained a smiling and satisfied expression, seeming but little affected by Josephine's terrible plight.

"I should very much like to know," continued the director, "why you said you knew the reasons for the threat being sent by this man to his mistress?"

Juve hesitated some moments; then, without going into details, said: "It would take too long to recount the motives which prompted Loupart to write that letter. This Josephine whom you see to-day trembling at her lover's threat not so long ago supplied the police with valuable hints concerning him. Has he learned that? Does he know the woman has rounded on him? Did he fear, above all, that she would tell tales again here at the hospital? It is quite possible. You see he must have had very strong reasons for giving her the order to come home——"

Juve here broke off, fingering Loupart's letter; then at length he placed it in his pocketbook.

"I will keep this document, director; it is a tangible proof of Loupart's criminal intentions. If he should put his threats into practice it would be difficult after that to deny premeditation."

"You think that such a thing is possible?"

"Don't you?"

"Loupart declares he will come to the hospital before three and kill his mistress, but surely it must be easy to render that impossible."

"You think the police are all-powerful, that we can arrest would-be murderers and render them incapable of harm? That is an error. We are prevented from taking effective action by a swarm of regulations. If I met Loupart on the street I would not be able to arrest him. I have no warrant. When a man holds his life cheap and is determined to risk everything, he has a pretty good chance of succeeding. Of course I shall take every measure to prevent Loupart killing his mistress, but I'm not at all sure of success."

"But M. Juve, we must have this girl Josephine transferred to another hospital if necessary."

Juve shook his head.

"And show Loupart we are aware of his purpose? Flatter the ruffian's vanity? No, we must let Loupart come, and catch him as he is about to commit the crime."

"What do you propose to do?"

"Study the hospital; arrange where to place my men," replied Juve.

"In that case, I will do everything I can to help you." M. de Maufil rang for an attendant and bade him take Juve to Doctor Patel's department.

Juve thanked the obliging director and took leave. The attendant pointed to a row of windows under the roof.

"Doctor Patel's division begins at the corner window and runs to the window near the cornice."

"What are the means of access to the female ward?"

"Oh, that's quite simple, sir; you get into the woman's ward either by the door on the staircase or by the door at the back, which leads into the laboratory of the head physician, the room of the house surgeon on duty, and the departmental offices."

"And how do visitors pass in?"

"Visitors always go up the main staircase."

"Now," said Juve, "show me over Doctor Patel's division."

"Very good, sir. It will be all the more interesting to you, as it is just the visiting hour."

When Juve made his way into the woman's ward, Doctor Patel was actually in process of seeing his patients. He was passing from bed to bed, questioning each of the women under treatment and listening to the comments of the house staff who followed him.

"Gentlemen," the doctor was saying as Juve joined the group, "the patient we have just seen affords a very excellent and typical instance of intermittent fever. The serum tests have not given any appreciable result; it is therefore impossible to arrive at——"

A hand was laid on Juve's shoulder.

"Why, the tests are always absolutely indicative! Palpable typhoid, eh? What do you think?"

Juve turned his head and could not suppress a cry of surprise.

"Doctor Chaleck!"

"What! M. Juve!—You here! Were you looking for me?"

Juve was dumbfounded. He drew Chaleck aside.

"Then you're attached to this hospital?"

"Oh, I have only leave to attend the courses."

"And I came here out of curiosity."

"In any case, allow me to thank you for the service you rendered me the other day. The officer who was with you seemed to take me for the guilty man."

"Well, you see, appearances...."

"But if anyone was a victim it was I. Apart from the finding of the murdered woman in my house, I have been robbed!"

Here the doctor broke off. A house surgeon was beckoning to him.

"Forgive me," he said to Juve. "I cannot keep my colleague waiting."

Leaving Chaleck, Juve went back to the attendant who had patiently waited for him.

"Stranger than ever!" he murmured. "There is no making it all out. Josephine writes that Loupart means to rob Chaleck. I track Loupart and he gives me the slip. I spend a night in a room where I see nothing, and where nevertheless a horrible amazing crime is committed. The murder takes place scarce a yard from me, and the doctor, the tenant of the house, sees nothing either, and does not even know the victim who is found next morning on his premises! Thereupon our informant, Josephine, goes into hospital; pain in the stomach, they say—hem! Poison, maybe? Then she gets a threatening letter from Loupart. And when I come to the hospital to protect her, whom do I meet but Doctor Chaleck!"

Juve, turning to the attendant who was escorting him, asked:

"You know the person I was speaking to just now?"

"Doctor Chaleck? Yes, sir."

"What is his business here?"

"He is a foreign doctor, I believe. I should fancy a Belgian. Anyhow, he is allowed by the authorities to follow the clinical courses and make researches in the laboratory."