“Possible!” agreed the Chief Constable. “But as to tracing him, we’ve done all we can here, and we’ve ascertained that he hasn’t turned up at any of his usual haunts in London, or in the City. Yet—he’s vanished! Suddenly, too! Now—why?” Blick paced the room again, thinking still more intently. “I wonder if Mrs. Tretheroe knows more than she’s told!” he said suddenly. “I’ve a conviction—a sort of intuition—that she does.” “I’ve had a suspicion of that sort all along,” answered the Chief Constable. “My own personal belief is that I don’t believe her a bit!” “Well,” said Blick, after more thought, “there’s one thing we can do.” “What?” “Go out there, both of us, this afternoon,” replied Blick. “Put pressure on her! Bluff her! Make her think we know something. Come with me, and leave the talking to me. I’ll force something out of her.” “Very good—after lunch,” agreed the Chief Constable. “It’s a chance!” Mrs. Tretheroe, alone in her boudoir late that afternoon, was neither surprised nor displeased when Daffy Halliwell announced the Chief Constable and Mr. Blick. The Chief Constable, as an ex-Army officer of rank, was likely to be quite agreeable as a visitor, and Blick was a young man of good looks and interesting personality. She welcomed both with some show of pleasure. “I hope you’ve brought me some news of Baron von Eckhardstein,” she said as she pointed them to chairs near her own. “It’s really most distressing that I’ve heard nothing yet, though I’m sure I’ve done everything that I could to find him in this neighbourhood—organized search parties and I don’t know what. Have you heard anything through your police people?” “A great deal, Mrs. Tretheroe!” replied Blick. Mrs. Tretheroe started and glanced sharply at the detective. These were not the tones in which he had addressed her on his previous visit—his voice now was official, firm, almost menacing; he spoke like a man who has got the whip-hand of the person he is addressing. And after her sharp glance at him Mrs. Tretheroe paled a little; she was conscious that two pairs of masculine eyes were fixed on her, not in admiration, but in something very like stern scrutiny. “What—what do you mean?” she faltered. “What is it—what’s happened?” “What has happened is this, Mrs. Tretheroe,” replied Blick. “We know a great deal more, now, than you seemed to think we know, about the recent doings of von Eckhardstein. Von Eckhardstein was the third man of the three who met at the Sceptre last Monday night—oh, it’s no use your protesting, Mrs. Tretheroe!—he was! It was he who went there at two o’clock in the morning, and—mind this!—he was the last man in whose company Guy Markenmore was seen alive!” Mrs. Tretheroe uttered a faint cry—evidently one of genuine astonishment. “No—no!” she exclaimed. “I can’t believe——”