"Not with a latch-key, as you did," she replied. "Madame Boisségur, at my suggestion, left the French window in the hall there unfastened, and I came in that way—the way, I may add, that Monsieur l'Ambassadeur went out when he disappeared."
"Very well!" commented Mr. Grimm, and finally: "I think, perhaps, I owe you an apology, Miss Thorne—another one. The circumstances now, as they were at our previous meetings, are so unusual that—is it necessary to go on?" There was a certain growing deference in his tone. "I wonder if you account for Monsieur Boisségur's disappearance as I do?" he inquired.
"I dare say," and Miss Thorne leaned toward him with sudden eagerness in her manner and voice. "Your theory is—?" she questioned.
"If we believe the servants we know that Monsieur Boisségur did not go out either by the front door or rear," Mr. Grimm explained. "That being true the French window by which you entered seems to have been the way."
"Yes, yes," Miss Thorne interpolated. "And the circumstances attending the disappearance? How do you account for the fact that he went, evidently of his own will?"
"Precisely as you must account for it if you have studied the situation here as I have," responded Mr. Grimm. "For instance, sitting at his desk there"—and he turned to indicate it—"he could readily see out the windows overlooking the street. There is only a narrow strip of lawn between the house and the sidewalk. Now, if some one on the sidewalk, or—or—"
"In a carriage?" promptly suggested Miss Thorne.
"Or in a carriage," Mr. Grimm supplemented, "had attracted his attention—some one he knew—it is not at all unlikely that he rose, for no apparent reason, as he did do, passed along the hall—"
"And through the French window, across the lawn to the carriage, and not a person in the house would have seen him go out? Precisely! There seems no doubt that was the way," she mused. "And, of course, he must have entered the carriage of his own free will?"
"In other words, on some pretext or other, he was lured in, then made prisoner, and—!"