"First-class story," said George, and as careless as you please flicked off his cigarette ashes on the rug. Mr. Whitney leaned forward clasping his big white hands between his knees and looking into my face, half-smiling but with something terrible keen behind the smile. "How can you be so sure of the voice, Miss Morganthau? I don’t know whether on the phone I could recognize the voice of my own son here." "You get that way in my work," I answered. "Your ear gets trained for voices." "You’re absolutely certain," said young Mr. Whitney, "that in that message you overheard, the man spoke of coming to the meeting place in his auto?" "Yes, sir, I’m certain he said that." He turned and looked at his father. "And investigations have shown he had no auto, he telephoned to no other garage for one, he kept no horses, and to get there on his own feet, would have had to walk through bad country roads a distance of twenty-five miles." "Um," answered old Mr. Whitney as if he wasn’t interested and then he said to me: "In this message you heard to-day no suggestion was given of what that key was the key of?" "No, sir. The man just said it was important and Mr. Cokesbury’d had the house upside down looking for it." "Um," said Mr. Whitney again. "I rather fancy, Miss Morganthau, you’ve done us a double service; in hunting for a voice, you’ve stumbled on a key." Young Mr. Whitney laughed. "It’s probably the key of his front door." "Perhaps," said his father, and looked down on the carpet as if he was thinking. Then Babbitts spoke up: "Don’t criminals, no matter how careful they are, often overlook some small clew that maybe is the very thing that gives them away?" "Often," said Mr. Whitney. "In most crimes there’s a curious lack of attention to detail. The large matters are well conceived and skillfully carried out. And then some minor point is neglected, sometimes forgotten, sometimes not realized for its proper value." He got up and shook himself like a big bear and we all rose to our feet. I was feeling pretty fine, not only the relief of having delivered the goods, but proud of myself for getting through the interview so well. Mr. Whitney added to it by saying: "You’re a pretty smart girl, Miss Morganthau. _You_ don’t know and _I_ don’t know yet the full value of the work you’ve done for me and my client. But whatever the outcome may be you’ve shown an energy and keenness of mind that is as surprising as it is unusual." I just swelled up with importance and didn’t know what to say. Behind Mr. Whitney I could see Babbitts’ face, all beaming and grinning, and I was so glad he was there to hear. And then—just when I was at the top-notch of my pride—Mr. George Whitney, who’d been silent for a while, said suddenly: "If you don’t mind me asking, Miss Morganthau, I’d like to know what lucky chance made you listen in to that conversation between Miss Hesketh and the Unknown Man."