Off the hall Markham saw a bedroom. Then a bath; finally, at the very end of the hall, a door to the left.
Markham stepped in there and pressed a light switch set in the far wall. The room was half study, half bedroom.
“My own quarters,” explained Amboy. “This is where I intend to sleep.”
“Only the one door,” observed Markham.
“Yes,” replied Amboy. “This is the end of the apartment.”
“Why don’t they have a window in this end wall then?”
“Because this is only one half of the building. There’s another apartment beyond. Similar to this one.”
“I see. Reached from the other side of the house, eh?”
“Yes.”
Markham looked about. He asked Amboy to make sure that nothing in the room was disturbed. That established, both men left, Markham turning out the light. They went into the living room. There they sat and chatted.
Peters Amboy became less nervous during the progress of a half hour. Finally he decided to turn in.
Markham agreed to sleep in the empty bedroom, leaving the dicks in the living room. He walked along the hall with Amboy. He stopped, turned on the bedroom light and looked around.
Amboy kept on. When Markham reached the hall, the man was just stepping into the study at the end of the hall. Markham saw the door swing shut; it did not quite close. Hence the detective saw the light from the room when Amboy turned on the switch.
The detective sergeant turned to go back to the living room. Then he came to a startled stop. From beyond that partly closed door of the study came the boom of a gun shot. As Markham stood rooted, he heard a gasping choke; then the thump of a falling body.
MARKHAM sprang along the lighted hall. The dick from the living room came dashing up to join him.
Together, they reached the study. Markham pushed the door open. He stared at the floor. There, five feet away, lay the sprawled form of Peters Amboy.
Markham advanced and stopped above the body. Amboy was dead. Looking about, Markham could see no one. The detective sergeant had drawn a gun. He spoke to the dick beside him, ordering the fellow to bring in the other detectives from the hall.
The dick hurried away. Rising, Markham moved slowly toward the door; then stood with revolver in hand. Two minutes later, the three-man squad joined him. Posting his aids, Markham stalked across the room and yanked open a closet door. The closet was empty.
Space showed beneath the couchlike single bed. No spot where a man could be concealed. Markham stepped over to Amboy’s body. He thought he had the solution. Suicide. Amboy had been nervous. He looked for a gun, beside or beneath the body. He found none.
Blinking, Detective Sergeant Markham arose and stared at the dumfounded dicks. Like Markham, the members of the squad were wearing whitened faces. They formed a group that could swear to astounding murder.
Every man — even the pair in the hall — had heard the fatal shot. All had arrived through the only door whereby an exit could have been gained. Yet they had found no trace of the murderer nor any sign of the weapon he had used.
Again, the Unseen Killer had delivered amazing death!
CHAPTER XIII. NORGAN SPEAKS
MIDNIGHT. Commissioner Wainwright Barth was standing in Amboy’s living room. He was surveying a group of men who had come here at his call. Findlay Warlock, Marryat Darring, Wallace Norgan; last of all, Lamont Cranston.
“I’m glad you happened to call the club, Cranston,” Barth was saying. “I reached Warlock at his home; Darring in the grille room of his hotel. Norgan, of course, was at his home, with Cardona guarding him.
“But I didn’t know where to reach you. That is why I left the message at the Cobalt Club. Because I wanted you to be here also. Every one who was present at Warlock’s should be here to learn the details of this new outrage by the Unseen Killer.”
Barth paused as Joe Cardona entered. The detective had come from the death room at the end of the hall. Joe nodded to indicate that everything was ready. They formed a procession down to Amboy’s study. They passed detectives in the narrow hall.
When they reached the death room, they saw Amboy’s body lying on the floor. Markham and a police surgeon were on duty.
“I want you all to hear the reports,” declared Barth. “Tell us exactly what happened, Markham.”
The detective sergeant gave the details as he knew them. When he had finished, Barth mentioned another matter — the fact that Markham had failed to cover the door after Amboy’s death.
“I muffed it, commissioner,” admitted the detective sergeant. “I remembered what you’d told me. We’ve got to figure that this Unseen Killer is around even when we can’t see him. I figured wrong. That’s all.
“Amboy had been jittery. Hadn’t been out of my sight all evening. Perked up some, just before he came in here. Then boom! — the shot comes all of a sudden. When I saw nobody in here, I thought that maybe it was suicide.
“It wasn’t till after I looked for a gun that I knew I was wrong. By that time, the squad had come in; I’d been away from the door. The Unseen Killer could easy have made his get-away.”
“Your frankness is commendable, Markham,” declared Barth. “Well, gentlemen, you see before you the evidence of a crime more startling than the murder of Nathaniel Hildon. Here, the Unseen Killer committed crime almost under the eyes of watching detectives.
“Look about. I want you to fully realize the difficulty that he must have encountered. Here is this room, just as it was when Peters Amboy was slain. There is the body. Let us hear the surgeon’s statement.”
“Would it be all right, commissioner, if I moved one of these floor lamps?” The question came from the police surgeon. “If I can get it closer to the body, I can show the wound more effectively.”
“Move one of the lamps if you choose.”
THE physician detached the cord of a lamp, pulling it from the floor plug. He carried the lamp to a spot only a few feet from the sprawled form of Peters Amboy. He carried the end of the cord to the wall switch.
There was a plug in the brass plate just beneath the switch. This plug was covered by a hinged brass disk, which the surgeon raised. He inserted the end of the lamp cord into the plug beneath. He turned on the lamp. A glow spread above Amboy’s body.
“The wound was just above the heart,” explained the doctor, in a methodical tone, stooping to indicate the body. “The range must have been about three feet. The man evidently staggered before he fell. It was impossible to tell exactly where he was standing when the killer fired.”
“I might indicate that, commissioner,” declared Markham. “But as the doctor says, it can’t be exact.”
“Show us,” suggested Barth.
“We’ll, he’d just turned on the light,” said Markham. “I don’t think the killer would have been mug enough to press the switch himself. So that puts Amboy here, to begin with.”
Markham went over and placed his right hand against the wall switch. He did not click it; instead, he stood there, facing the wall. He held up his left hand.
“I’ll give you the interval,” he said. “As near as I can remember it.”
He retained his position for a few moments; then lowered his left hand. Without turning, he spoke again.
“You see,” he said, “I turned on this light about a half hour before Amboy did. That was shortly after he and I got into the apartment. I was looking around the place. So I can figure sort of what a man might do after turning on the light.
“He’d either look around” — Markham turned his head to the left — “or he’d turn around.” He swung his body to the left. “This direction. Because he’d be coming into the room and the room is to the left.