"That's strange," declared the detective. "I kept an eye on Josephine myself, thinking that a movement on her part would betray the entrance of Loupart. She made no sign; but, however Loupart may have got in, he can't get out without falling into a trap. I have fifty men posted round the building. Now, the first point to clear up is the exact place from where the shot was fired." "How can we get at that?" "Very simply. By drawing an imaginary line between the spot where the bullet struck the mattress and where it went into the floor--extend this line and we find the quarter from where the shot was fired." A doctor came forward. "M. Juve," he said, "that would bring us to the door of the staff's room." "Ah, it's you, Doctor Chaleck! I'm glad to see you! You are quite right in your surmise. Do you see any objection to my reasoning?" "I do. I came into the ward barely two seconds before the firing. No one was behind me and no one was walking before me." Juve crossed to the door. "It is from here that the shots were fired!" And the detective added triumphantly as he stooped and picked up an object from the floor: "And this backs up my assertion!" He held out a revolver, still loaded in four chambers. "A precious bit of evidence!" He turned to the doctor: "Can a stranger get into the wards by this door?" "Utterly impossible, M. Juve! Only those thoroughly familiar with Lâriboisière can get into the ward through the laboratory. You must pass through the surgical divisions." The detective seated himself at the foot of the sick woman's bed and mechanically laid the revolver beside him. But scarcely had he done so when he sprang up. Upon the sheet was a tiny red speck left by the muzzle of the weapon. "Ah!--that's very instructive!" he cried. And as the others crowded round, puzzled, Juve added: "Don't you see? The murderer ran his finger along the barrel to steady his aim, and as the barrel is very short, the bullet grazed the tip of his finger which extended slightly beyond it. If I find anyone in the hospital with a wounded finger, I've got the murderer! Gentlemen, I am going to ask the director to issue orders for everyone within the hospital gates to pass before me. I reckon that in two hours at most the culprit will no longer be at large." * * * * * The attempted murder happened at three o'clock; about six o'clock, those who had first been examined by Juve had received permission to leave the hospital and were beginning to depart. With a careless step Doctor Chaleck made for the exit by which he issued every evening from Lâriboisière. As he was about to pass out, a police inspector barred his way. "Excuse me, sir. Have you a pass?" "A pass?" "Yes, sir; no one is allowed to leave to-day without a pass from M. Juve." The doctor looked at his watch. "The deuce," he said. "I'm late as it is. Where am I to get this pass?" "You must ask M. Juve himself for it. He is in the director's private room."