"It sounded like a voice on a speaking machine."
The colonel nodded slowly.
"Now you come to mention it, I think you're right," he said; "it sounded familiar to me. Of course, it was a gramophone voice."
They made a careful search of the apartment, taking down every book from the big shelf in one of the alcoves, and turning the leaves to discover the hidden machine. With this idea to guide them the search was more complete than it had been before. Every drawer in the desk was taken out, every scrap of furniture was minutely examined, even the massive legs of the colonel's writing table were tapped.
Crewe took no part in the search, but watched it with a slight smile of amusement, and the colonel turning, detected this.
"What the devil are you grinning about?" he said. "Why aren't you helping, Crewe? You've got an interest in this business."
"Not such an interest that I'm going to fool around looking for a gramophone voice that goes off at appropriate intervals," said Crewe. "Doesn't it strike you that it would have to be a pretty smart gramophone to chip in at the right moment?"
The colonel pondered this a minute and then went back to his place at the table, mopping his forehead.
"Pinto's right," he said; "the fellow has smuggled some fool machine into the flat, and we shall discover it sooner or later. I don't know how he controls it, or who controls it"—he looked suspiciously at Crewe—"or who controls it," he repeated.