“I hate this job,” she said. “I hate prying and spying. I’m through. I can’t go on. I can’t send a woman to the chair.”

He knew her through long association. He realized that in her present mood he could not push her.

“It was a woman?” he said quietly.

She nodded.

“How was it done, Hilda?”

“It had to be done by someone who knew the house,” she said slowly. “Someone who knew the light circuits. Someone who knew this radio and had a chance sometime to discover how to adjust the remote-control phonograph. It didn’t need much. It could be done in a few minutes. After you find the blank spot on the radio, all you have to do after that is to turn the dial to that spot. Then you could start the record, and it would play here.”

“Where was it played from just now?”

“There’s a young man in Carlton’s room,” she said dully. “I promised him ten dollars to come tonight. I’d better pay him and let him go.”

He gave her the ten dollars and she went out. She was gone a considerable time. When she returned she looked so pale that the inspector thought she was going to faint.

“He left the machine,” she said. “He’ll get it in the morning. If you want to see it—”

“See here, I think you need some whisky.”

“No. I’m all right. If you’ll come along I’ll show you.”

She got up heavily and led the way. Carlton was still downstairs with Susie, but his room was lighted. Sitting on the floor by a base outlet was what looked like a small phonograph about a foot in diameter, with a record on it. It was plugged into the wall, and the inspector, picking up the record, saw that it was the Habanera from Carmen. He started it, and going to Mrs. Fairbanks’s room switched on the radio. Almost immediately the Habanera started. He switched it off, and went back to Hilda. She was still there, standing by a window.

“How long have you known about this?” he demanded.

“Only today. Something Susie said. I saw the radio set where it is, and—I wondered about it. You see, there are almost no stations on the air at one or later in the morning, and when they are it’s dance music. I had just remembered it was something from Carmen that night. I should have thought about that sooner,” she added, and tried to smile.

He had an idea that she was playing for time. He was wildly impatient, but he did not dare to hurry her.

“You see, it didn’t take long,” she went on. “I’ve tried it. Two minutes was enough to use the knife and turn the radio dial to the blank spot. And the doctor was in Jan’s room for five minutes, maybe more. Even at that she took a chance. A dreadful chance,” she said, and shivered. “She wasn’t quite normal, of course. Those bats and things—”