Turnbull started to answer, but, at that moment the door opened.
The round, pleasant-faced gentleman who came in needed no introduction to Turnbull.
Scholar Duckworth said: "Hello, Dave. Sorry I wasn't here when you woke up, but I got—" He stopped. "What's the matter?"
"I'm just cursing myself for being a fool," Turnbull said sheepishly. "I was using your disappearance as a datum in a problem that didn't require it."
Scholar Rawlings laughed abruptly. "Then you thought—"
Duckworth chuckled and raised a hand to interrupt Rawlings. "Just a moment, Jason; let him logic it out to us."
"First take these straps off," said Turnbull. "I'm stiff enough as it is, after being out cold for three days."
Rawlings touched a button on the wall, and the restraining straps vanished. Turnbull sat up creakily, rubbing his arms.
"Well?" said Duckworth.
Turnbull looked up at the older man. "It was those first two letters of yours that started me off."