10/44 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. |