Lady Laura slid in a sentence here.
"Dear Mr. Baxter, you need not be in the least alarmed. All that has passed here is, of course, as sacred as in the confessional. We should not dream, without your leave—"
"One moment," gasped the boy.
He drove his face into his hands and sat overwhelmed.
Presently he looked up.
"But I knew it," he said. "I knew it. It was just my own self which spoke."
The medium smiled.
"Yes," he said, "of course that is the first answer." He placed one hand on the table, leaning forward, and began to play his fingers as if on a piano. Laurie watched the movement, which seemed vaguely familiar.
"Can you account for that, Mr. Baxter? You did that several times. It seemed uncharacteristic of you, somehow."
Laurie looked at him, mute. He remembered now. He half raised a hand in protest.