He re-pictured his clues.
“The grind of moving rocks on the records. None in real rocks. A thump on the record. How do they tell me anything? The record was not really made in Tibet. It was made in America. I seem to remember that the Tibet voice was deeper than the one on the record. But why did the record add something not in Tibet? The rock rasp. Is that my real clue?”
Puzzling about it, and trying to see what link there was between the thump and that additional grinding sound, he got no inspiration.
His meditation was interrupted by the arrival of a caller, a man from the Museum of Natural History.
He wanted the laboratory to work out some extremely complete system for protecting the museum’s very valuable collections, such as the gem exhibit, and other priceless collections.
Roger had to explain the absence of his cousin on “business” and to accept the assignment conditionally on Grover’s acceptance.
“Probably some short-wave system could be worked out,” he said, and the caller left.
Grover telephoned. Told of the call, he agreed to accept the commission and would call at the museum before coming to the lab., when relieved by Potts toward nightfall.
Roger went back to his broken thread of meditation.
An attempt had been made to get into his room. Millman had been caught. His motive, he had said, was to learn whether Roger played scientific tricks. Did that ring true? Or, as Roger felt, could he have wanted to silence a tongue able to accuse him about Astrovox?