Brainard stopped again beside her desk.
"All that is neither here nor there," he remarked, forcing a change in his manner. "I am in for it. Now, the question is—what are we going to do about it!"
Constance had unwrapped the package on her desk, disclosing an oblong box.
"What's that?" he asked curiously.
"Mr. Brainard," she answered tapping the box, "there's no limit to the use of this little machine for our purposes. We can get at their most vital secrets with it. We can discover every plan which they have against us. We may even learn the hiding place of those letters Why, there is no limit. This is one of those new microphone detectives."
"A microphone?" he repeated as he opened the box, looked sharply at the two black little storage batteries inside, the coil of silk-covered wire, a little black rubber receiver and a curious black disc whose face was pierced by a circular row of holes.
"Yes. You must have heard of them. You hide that transmitter behind a picture or under a table or desk. Then you run the wire out of the room and by listening in the receiver you can hear everything!"
"But that is what detectives use—"
"Well?" she interrupted coolly, "what of it? If it is good for them, is it not just as good for us?"
"Better!" he exclaimed. "By George, you ARE the goods."