“About that telephone,” Tragg insisted, putting a hand on Karr’s wheelchair.
“What about the telephone?” Karr asked, his voice gone flat with weariness.
Tragg said, “We have reason to believe that the person who committed that murder had a very definite reason for lifting the telephone receiver.”
Mason avoided Tragg’s eyes.
Karr said, “I suppose he wanted to call someone. You have to lift the receiver to do that, you know.”
“When we first examined that telephone,” Tragg went on, ignoring Karr’s sarcasm, “we noticed only an ordinary desk telephone with two fingerprints which had been outlined in paint on the receiver. Then we made a more detailed investigation and found something which is very peculiar, to say the least.”
Karr said, “Don’t beat around the bush. If you’re trying to accuse me of something, come out and say so.”
Mason said, “He’s just trying to surprise you into an admission of something, Mr. Karr. It’s the way the police work. Apparently a person’s poor health doesn’t change their methods.”
“I’m not accusing you of anything,” Tragg said, ignoring Mason’s interpolation, “but I’m telling you what we found.”
“Well, what did you find?”
“Concealed in the base of that telephone in such a way that it would hardly be noticeable on a superficial examination was a small hole. The telephone was bolted to the desk, which was unusual. We further found that the desk was screwed to the floor so that the telephone and desk were held in one position. That aroused our suspicions. We made a careful examination and found that the base of the telephone contained a very ingenious burglar alarm, a ray of invisible light which could be switched on so that it played across the door of that room. The only way the connection could be broken was by throwing a switch which was on the far side of the light beam, or by picking up the telephone receiver and lifting it from its cradle, which automatically had the effect of cutting off the beam of light.”
Karr said, “It doesn’t mean a damned thing to me. I fail to see why you are telling me about it.”
“Because,” Tragg went on patiently, “when any person walked across this beam of light without first lifting the telephone receiver, it caused a buzzer on the screen porch of the lower flat to sound. And that buzzer, Mr. Karr, was fastened to the side of the house so that it was directly below your bedroom window!”
Karr placed his thin, wasted hand on the arm of the chair, gripped it so that the cords stood out plainly under the skin of the back of his hand. “Buzzer — under my window. Then that explains it.”
“Explains what?”
“That must have been what wakened me first, before I heard anything. I heard a peculiarly insistent sound which was like the buzzing of mosquitoes. It was high-pitched, distinctly audible, very irritating to a man of my nervous temperament. I kept listening, thinking at first it was a mosquito in the room, then realized that the sound was coming from outside of my window.”
“How long did it continue?” Tragg asked.
“Some little time. I don’t know how long it had been going before I woke up.”
“How long before you heard the shots?”
Karr said firmly, “There was only one shot.”
Tragg sighed. “I take it,” he said, “I am indebted for the other shot to the versatile mind of Mr. Mason.”
Karr said testily, “You are indebted for the extra shot to what I told Mr. Mason. At the time, I thought there might have been two shots. Since then, and on thinking it over, I have come to the conclusion that there was only one shot, and perhaps an echo from the side of the adjoining house.”
“And how about the buzzing?” Tragg asked.
“The buzzing,” Karr said, “continued for a few minutes after the sound of the shot, and then ceased.”
“Think carefully. Did you hear it again?”
“No,” Karr said positively. “I didn’t hear it after that.”
Tragg studied him for a moment, then said, “It would have simplified matters if you’d told me this stuff when I first questioned you.”
Karr, staring right back at him, said, “And it would have simplified matters if you’d told me about the telephone receiver.”
“I didn’t know about the burglar alarm then.”
“And I didn’t know that the buzzing of a mosquito was important.”
“Then there was only one shot?”
“I’ve come to the conclusion now there was only one shot.”
“Do you know what time it was?”
“I can’t tell you exactly, no. It was sometime after midnight, and I would say before one o’clock. And now if you’ll excuse me, Lieutenant, I’m going to retire. I’m not going to drive myself past the danger point for anyone. I’ve already put up with more than I should.”
Without another word, Karr lowered his hands to the rubber tires of the wheelchair. But quick as he was, Gow Loong was the first to apply the pressure against the wheelchair which sent it into motion toward the rear of the house.
Doris Wickford said to Mason, “Apparently I’m to camp on your doorstep until this is cleaned up.”
Rodney Wenston shook his head. “I know the guv’nor pretty well,” he said. “Don’t rush him. He won’t do a thing if you crowd him.”
Lieutenant Tragg said to Mason without any more expression in his voice than if he had been commenting on an unusual spell of weather, “Certainly is strange the number of coincidences there are in this case. And every time I come here I find you here.”
Mason laughed. “I think of it as being the other way around. Every time I come to talk with my client, you manage to drop in. I was thinking that perhaps I was being followed.”
“It might not be a bad idea at that.”
Tragg started toward the stairway, then paused as he was near the first step, and beckoned Mason over to him.
“I see nothing for it but to arrest young Arthur Gentrie and charge him with murder.”
“Whose murder?” Mason asked.
Tragg smiled amicably. “Thought you’d catch me on that one, didn’t you? Well, just to put your mind at rest, when we discovered the body of Mrs. Perlin, we made a complete search of the premises. We went through everything, even cleaning out the ashes in the furnace, and in those ashes we found some interesting things, a few bits of charred cloth, some buttons, the remnants of a pair of shoes. On the portions that hadn’t been completely destroyed by fire, we found dark stains. An analysis shows they were made by human blood. You might think that over, Mason. And now if you’ll pardon me, I’ll run along. I want to talk with young Gentrie as soon as he gets back from the hardware store.”
Chapter 14
Mason got Della Street on the telephone a few minutes after five o’clock.
“Closing up?” he asked.
“I was waiting for you. How’s everything going?”
“Oh, so-so. Want to take a trip?”
“Where?”
“San Francisco.”
“How?”
“Reservations on the six o’clock plane. I’ll meet you at the airport.”
Della Street said, “A dab of powder on my nose, and I’m headed for the elevator.”
“Okay,” Mason said, “make it snappy. I’ll be aboard the plane. There’ll be a ticket for you at the ticket window. Just pick it up and climb aboard.”
“Be seeing you,” she promised, and hung up.
The late afternoon rush was on at the airport. Speeding cars came dashing in or went roaring out. People milled around in little groups, saying farewells or greeting arriving passengers. The loud speaker blared forth the fact that the six P.M. plane for San Francisco was ready for departure, and Mason, giving one last look around, was starting for the gate when Della Street came sprinting through the door. She gave him a friendly wave of her hand, then ran over to the ticket window to pick up her transportation. She joined him as he was getting on the plane.