“Odd deaths,” came a quiet interruption. “Yet ones that do not belie Crofton’s story.”
Barth turned to Cranston. It was he who had spoken.
“Can you explain those killings?” challenged the commissioner.
“Possibly,” rejoined Cranston, with a quiet smile.
“How?” demanded Barth.
“Lessep, to begin with,” remarked Cranston. “No bomb was thrown at him. He died by a special device planted in his little office. One so clever that it passed unsuspected.”
“How do you know that?”
“I found a used lamp bulb in his desk. I happened to try it. The bulb was not burned out.”
“This is no time for a hoax!” cried Barth. “What did such a bulb have to do with Lessep’s death?”
“It proved,” returned Cranston, “that there must have been some purpose in its removal. For instance, a special bulb, screwed into the lamp above Lessep’s filing cabinet. One that was left loose—”
“For what purpose?”
Cranston stepped across the room. He unscrewed a light bulb in its socket, leaving it loose. The others watched the demonstration, particularly Joe Cardona.
“Picture Lessep coming into his laboratory,” remarked Cranston. “To get those photographs. The last act he was to perform. He tries the light switch” — the speaker demonstrated — “and no light results. He decides to remove the bulb, thinking it burned out.”
Cranston’s long fingers began to turn the bulb. They stopped, apparently noting its looseness.
“A loosened bulb,” he remarked quietly. “Lessep decides to screw it tight before removing it. He does so. Contact forms and—”
“He gets light,” put in Barth, as the lamp came on.
“No,” returned Cranston. “Not with the bulb that was placed there. That bulb was a bomb, its mechanism hidden by the frosted glass.”
“Ready to blow when the current hit it!” cried Cardona. “That’s the story, commissioner! I see it!”
“DID you suspect this at the time?” demanded Barth, speaking to Cranston.
“Yes,” was the reply.
“Why, then,” asked the commissioner, “did you fail to mention it?”
“Because I suspected all that Crofton has told us. I knew there could be no Unseen Killer. Deducting from that basis, I knew that Professor Lessep had himself taken the lever from his machine; that he had typed the threatening note found on his desk. Lessep was a fanatic. I could well believe—”
“That he planted the bomb himself? As a means of suicide?”
“Yes. At the same time it was possible that an enemy had placed the bomb. I suspected one of two men. Lessep was dead. It was best to wait.”
“Why?”
“In case the real killer would show his hand. So that he could be trapped in actual murder.”
“You should have advanced your theory, Cranston. Hildon — Amboy— Norgan—”
“All died through their own errors.”
“How so?”
“The killer did reveal himself,” explained Cranston, “by his first notes. To Hildon, Amboy, and Norgan. Had they acted sanely, and informed you of the threats, I would have told you what I had learned. But they were avaricious. They had gained wealth by legalized crime. They kept their secret. Hildon died.”
“Can you explain his death?” demanded Barth.
“I have a theory,” said Cranston, quietly. “A sound one.”
“Of how a visible killer could have left Hildon’s room?”
“Yes.”
“How?”
“By the side window.”
“Impossible! It was locked on the inside. The panes were intact.”
“Exactly. But suppose” — Cranston paused and adopted a tone that was almost speculative — “suppose some one had climbed to the porch roof outside the window. While Hildon was at dinner, the intruder could easily have chiseled away the painted putty that held one pane in place.
“Entering, leaving the glass on the roof, that man could have strangled a weakling such as Hildon. Then out through the window. The pane back in position. New putty, of the type that hardens rapidly. Quick-drying paint which—”
“That’s the story, commissioner!” exclaimed Joe Cardona. “It’s no theory. Mr. Cranston is telling you facts. That’s why the telephone bell was wadded.”
“The telephone bell?” queried Barth.
“Yes,” replied Cranston, with a smile. “So Hildon’s body would not be found until morning. It was found sooner; but not too soon.”
“You’re right,” agreed Cardona. “I was too dumb to think of the windowpane. That stuff had time to dry anyway. Say — maybe there’s a lot of cracked putty on that roof—”
“There should be some,” inserted Cranston, dryly. “Probably the murderer spread a cloth to catch most of it. But I advise you to go down there, Cardona. You will probably find traces now that you know where to look.”
“CRANSTON,” declared Barth, seriously, “this is something else you should have mentioned. Lives were at stake when—”
“Whose lives?”
“Amboy’s and Norgan’s.”
“Not at all. Their wealth was at stake. They promised to deliver it to the Unseen Killer. That was why I waited. Had they delivered it two nights ago, the murderer might easily have been traced.”
“You mean they tried to trick him then—”
“Exactly! That was fair, perhaps. But they played false with you as well.”
“So they did. That’s right. That’s why Amboy died. But how—”
“I was interested at Amboy’s,” interrupted Cranston, quietly. “Detective Sergeant Markham gave us an excellent demonstration of how Peters Amboy might have died. But Markham was deluded by his belief in an invisible murderer.
“He mentioned — perhaps you remember it — that Amboy could have been killed while facing the wall. But he could not follow that theory because there was not sufficient space between Amboy and the wall.
“Yet Amboy did die while in that very position. The shot, commissioner, came through the wall itself.”
“Through the wall?”
“Yes. By way of the plug socket underneath the light switch. You remember it? The plug with the little hinged lid that dropped so easily into place?”
“I remember it,” put in Cardona.
“Good,” remarked Cranston. “Suppose, Cardona, that there is a similar switch and plug in the next apartment. Both on the same wiring. Picture a murderer stationed in the next apartment. A tricked murderer — one who has found a box containing blank paper — one who had planned this death beforehand.
“He comes to the empty apartment. He removes the light switch. He takes out the plug from Amboy’s switch on the opposite side of the wall. He pushes a gun muzzle right through, into the darkened room on the other side.”
“With the metal cap going up!” cried Cardona.
“Yes,” agreed Cranston. “Then Amboy enters. He turns on the light. The murderer sees the glimmer. He fires at a man perfectly located. Back comes the gun. Down drops the metal plug cover—”
“And the killer fixes the whole works while Markham is looking at Amboy’s body!” Cardona was excited. “All it took was nerve. Then a get-away from the empty apartment on the other side of the building!”
“Most amazing!” declared Commissioner Barth, sternly. “Yet it does you no credit, Cranston. A man has died to-night — Wallace Norgan — and you could have saved his life.”
“Yes,” admitted Cranston, in a solemn tone. “Unfortunately, I was too late in my arrival. I intended to be here, but” — a slight smile — “other matters detained me.”
“Something more important than the saving of a human life?”
“Hardly” — keen eyes turned to note Crofton, half asleep in his chair. To The Shadow, Crofton, honest but duped, was more valuable a man than Norgan. “It was a matter of choice, commissioner. However, I saw no danger for Norgan. If he had gone through with what he started, giving up funds that did not rightfully belong to him, he would not have died.