The pounding on the door became hysterical, and Cassidy, who for two cents would have become hysterical himself, went over and unlocked it. He found Dr. Worth, backed by scandalously excited servants and flanked by Nurse Murrow and O’Brian, pressing across the sill.

“Is it Endicott?” Dr. Worth demanded breathlessly.

“No, sir⁠—it’s Hollander. We shot the knife from his hand before he could stick it into Endicott, and then we shot him down.”

“Close this door, Officer, and keep these people out. Come in with me, Miss Murrow.”

Dr. Worth came into the room with Nurse Murrow. Cassidy closed the door, and the shrill clatter of excited whisperings ebbed like a tide.

“Thank God, Officer, you saved Endicott. What a mess.” Dr. Worth glanced critically at Hollander, huddled on the floor by the bed in a blood-soaked heap. “You two men help Nurse Murrow. Stretch him out on that chest over there by the window. Do what you can for him, Miss Murrow, until I’ve taken care of Endicott.”

Cassidy and Hansen lifted Hollander and carried him to the improvised cot Miss Murrow arranged with blankets and a pillow on top of the mahogany chest by the window.

Nurse Murrow then became the acme, the pink of proficiency. She dressed and bound Hollander’s wounds, and applied the proper tourniquet above his shattered wrist. In her opinion, his condition was not fatally serious, when one considered his obvious physique and his probably excellent constitution⁠—of iron⁠—and, yes, he was distinctly handsome. What a pity they’d arrest him. Or perhaps he was under arrest already, although she usually associated handcuffings with arrests. But there surely wouldn’t be any handcuffs now. In spite of her long familiarity with dreadful injuries she shuddered a little at that shattered wrist. And they couldn’t be so soulless as to move him to prison. Dr. Worth would never permit any patient of his to be treated like that. And, after all, Hollander was the doctor’s patient.⁠ ⁠…

Dr. Worth himself was standing beside her. There was a bewildered, curiously grave look on his face. She sensed intuitively what had happened.

“Mr. Endicott, Doctor?”

Dr. Worth shrugged helplessly. “He’s dead.”

“But I swear that knife never went in, sir,” Cassidy said. “Hansen, here, and me was watching Hollander like cats. Sure we saw the knife even before it touched the bedclothes.”

“Didn’t Hollander have a gun, too?”

“No, sir. Why do you ask?”

“Because Endicott was killed by a bullet.”

Hansen’s Nordic young face grew very red and then very white. Cassidy showed nothing of what he was thinking⁠—certainly nothing of the sickening, puzzled worry that clamped his chest⁠—except that there was a tight clenching of his hands.

“Too bad,” Cassidy said.

“Yes,” agreed Dr. Worth, “it is too bad.”

“You’re sure, sir?”

Dr. Worth grew icily formal. “Quite,” he said. He was also getting good and mad. This was the sort of thing, he told himself angrily, that taxpayers shelled out their money for. Protection! It was enough to make anybody laugh. A lot of protection the police force of New York City had been for Endicott. They’d shot him⁠—that’s what.

“But I don’t see how⁠—”

“Officer, there is no mistaking the difference between a bullet wound and one made by a knife. In this case especially it is perfectly obvious. I dare say the charge against you two men will be just technical⁠—accidental homicide in line of duty!”

Dr. Worth did permit himself one short laugh.

“I guess so, Doctor,” Cassidy said.

“And is there anything that has to be done, Officer?”

“In what way, sir?”

“Why, a report made to the medical examiner?” Dr. Worth became almost airy in his mounting anger. “This sort of starts the whole thing over again, doesn’t it? I mean, won’t the medical examiner have to come back up and investigate before we can move the body and⁠—oh, well, you know the line.”

“Maybe so, sir.” Cassidy’s face was the colour of a red tile brick. “Cripes, but I wish the lieutenant was here.”

“I understand that he will be here any minute.”

“You’ve heard from him, sir?”

Dr. Worth felt that if he didn’t apply the brakes he would become positively lightheaded. “Oh, yes, yes, indeed, Officer. He called up to warn me that my patient was going to be murdered and suggested that I run downstairs and stop it. Murder? Fiddlesticks⁠—it’s beginning to graduate into a catastrophe.”

“What has happened here?”

Lieutenant Valcour, very pale, still very weak, and with an improvised bandage around his head, had come unobserved into the room.

“You can see,” Dr. Worth said with almost insulting distinctness, “for yourself.”

Dr. Worth then went on to expand. He related in detail his version of the battle⁠—he insisted that it was a battle⁠—which had just taken place.

Entirely apart from the natural discomfiture of his head, Lieutenant Valcour was feeling desperately glum. Under no light, no matter how favourable, could his handling of the case be considered a success. He had to his credit one slap on the face, a good crack on the head from a lead slug, and now it seemed that the very man whom they had been ordered to guard had been shot and killed by his own men. That, at least, was the impression the angry bee talking to him was obviously trying to give. Oh, it would be a cause célèbre all right, but he shuddered to think of just what it would be celebrated for.

“This,” he said, “is nonsense.”

Dr. Worth was by now thoroughly acid.

“I am glad that you are able to find in the miserable situation some element of humour, Lieutenant.”

“Humour? Not humour, Doctor. I am just trying to say that the probability of Endicott’s having been shot by one of my men is nonsense.”

“Would it convince you, sir, were I to remove the bullet and let it speak for itself? Imperfections in the barrel leave their markings, don’t they? You can then doubtless determine which one of these two young men fired the unhappy shot.”

“Please don’t get irritated, Doctor. I’m not trying to annoy you or to be funny. It’s simply that I cannot see⁠—just where is the wound located, Doctor?”

“In the chest.”

“Cassidy, where were you and Hansen standing?”

“We was crouched on the floor just inside the room, sir⁠—not over five feet off from Hollander,” Cassidy said.

“Then consider your angles, Doctor. There’s Endicott⁠—there’s about where my men were crouched. It would take pretty wild shooting for either of them to hit Endicott in the chest. In fact, one might almost consider it impossible.”

Dr. Worth still hovered around zero. “From the number of innocent bystanders whom one reads about in the newspapers as having been shot down by the police⁠—”

“That is an unfair comparison, Doctor. Those cases you refer to have all involved a chase of some sort⁠—rapid motion⁠—streets cluttered up with people. There was nothing like that here. I’m going to call up Central Office and ask permission for you to remove the bullet and determine the angle of its path.”

“Permission, sir? And do you think it is my business or my pleasure to go probing about for bullets and determining the angles of their paths? I happen to be a specialist, sir⁠—”

“Yes, yes, Doctor. But right now it is your business to do just that. We must have the information immediately.”

“And why so, sir?”

“Because if the calibre of the bullet that killed Endicott differs from the ones in the guns of my men, or if the angle of its course proves conclusively that it could not have been fired by one of them, then the murderer is still loose about the house. He couldn’t have escaped, you see, as the guards are still on duty down below.”

… Then the murderer is still loose about the house⁠ ⁠…

The chilling possibilities of the statement served a good deal to cool Dr. Worth’s steaming indignation. He was getting tired with being angry, anyway.

“I’m sorry I have been impatient, Lieutenant. You may be quite right, and I’ll be glad to help you in any way that I can.”

“Thank you, Doctor. I’ll telephone Central Office from downstairs, as I want to instruct the men on guard down there to be doubly careful. If you’d care to start in probing it will be quite all right. I’ll explain everything to the medical examiner. It’s something, you see, that we must know. Cassidy, you and Hansen are not to leave this room. Search both it and Hollander for a gun.”

“Yes, sir.”

Lieutenant Valcour went out, and Dr. Worth proceeded, with the aid of Nurse Murrow, to probe.

The room had an air about it of a shambles. Cassidy and Hansen, having searched for a gun and found none, leaned dispiritedly against the wall near the chest on which Hollander was lying. They felt a measured sense of relief⁠—had felt it, in fact, from the moment when Lieutenant Valcour had come into the room. Each knew he could never have fired that shot which had killed Endicott. And each was reasonably certain that the other couldn’t have, either.

They could determine nothing from Dr. Worth’s face as to how the examination was going. Neither of them looked very closely at what he was doing. Their wonderings ran along parallel lines: Hollander couldn’t have had a gun or they’d have seen it or found it during their recent search. None of their shots could have gone so hopelessly wild as to have hit Endicott. But somebody did have a gun, and Endicott had been shot by it. But there had been nobody in the room with Endicott except themselves and Hollander. And Hollander couldn’t have had a gun, or they’d have seen it⁠ ⁠… the perfect loop continued on and on. Each made the circle in his thoughts and then started in all over again. If Lieutenant Valcour hadn’t reentered the room, and if Dr. Worth hadn’t just then extracted the bullet, they probably would have gone mildly mad.

“Everything’s all right, Doctor,” Lieutenant Valcour said. “The medical examiner was only too pleased at your kindness in helping him out. He won’t be up again tonight unless I send for him. He asked me to thank you.”

“Not at all, Lieutenant.” Dr. Worth showed considerable excitement. “You know, it’s surprising. I don’t know much about the calibre of bullets, but I think you’re right about the angle. Here’s the bullet.”

Lieutenant Valcour inspected a leaden pellet curiously and then slipped it into a pocket.

“It isn’t from one of our guns, Doctor,” he said.

“I’m not surprised, Lieutenant⁠—not surprised at all. Because the angle it entered at⁠—why, damn it, Lieutenant, it must have been fired from some place over there.”

Dr. Worth indicated a problematic area which included the corner where Hollander was stretched out. Lieutenant Valcour looked just above Hollander at the window. It was the window which had been opened about six or seven inches from the bottom by Nurse Murrow so that the air for her patient would be quite fresh and clear.

It was still open.

And outside of it, as Lieutenant Valcour very well knew, ran the shallow balcony which offered not only adornment to the rear of the house but a passageway to⁠—and from⁠—the windows of Mrs. Endicott’s room.

But Mrs. Endicott was under the influence of a narcotic, and a nurse and a maid were both in the room with her.

But were they?⁠ ⁠…