“Hold that tight against the safe door, Cecil. Get the base in contact with the metal of the safe and keep the microphone face downwards. It’s essential to hold it absolutely steady, for the slightest vibration will put me off.”
He fitted on the head-band and moved the two tiny levers of the otophone until the adjustment of the instrument seemed to satisfy him. Then, very cautiously, he began to work the mechanism of the combination lock. For some time he seemed unable to get what he wanted; but suddenly he made a slight gesture of triumph.
“It’s an old pattern, as I thought. There’s no balanced fence arbour. This is going to be an easy business.”
Easy or not, it took him nearly a quarter of an hour to accomplish his task; for at times he obviously went astray in the work.
“Try to keep your feet still,” he said. “Every movement you make is magnified up to the noise of a pocket avalanche.”
At last the thing was done. The safe door swung open. Sir Clinton took off the head-band, received the microphone from Cecil, and packed it away in the case of the otophone along with the ear-phone.
“You’d better jot down the number of the combination, Cecil,” he suggested. “It’s on the dial at present.”
While Cecil was busy with this, the Chief Constable switched off the otophone and put it in a place of safety.
“Now we’ll see what’s inside the safe,” he said.
He swung the door full open and disclosed a cavity more like a strong-room than a safe.