"It gives one explanation, at least," Mr. Grimm assented musingly. "Kidnapped—held prisoner—fifty thousand dollars demanded for his safety and release." A pause. "And to whom, may I ask, was this demand addressed?"
"To Madame Boisségur," replied Miss Thorne. "I have the envelope in which it came. It was mailed at the general post-office at half-past one o'clock this afternoon, so the canceling stamp shows, and the envelope was addressed, as the letter was written, on a typewriter."
"And how," inquired Mr. Grimm, after a long pause, "how did it come into your possession?" He waited a little. "Why didn't Monsieur Rigolot report this development to me this afternoon when I was here?"
"Monsieur Rigolot did not inform you of it because he didn't know of it himself," she replied, answering the last question first. "It came into my possession directly from the hands of Madame Boisségur—she gave it to me."
"Why?"
Mr. Grimm was peering through the inscrutable darkness, straight into her face—a white daub in the gloom, shapeless, indistinct.
"I have known Madame Boisségur for half a dozen years," Miss Thorne continued, in explanation. "We have been friends that long. I met her first in Tokio, later in Berlin, and within a few weeks, here in Washington. You see I have traveled in the time I have been an agent for my government. Well, Madame Boisségur received this letter about half-past four o'clock this afternoon; and about half-past five she sent for me and placed it in my hands, together with all the singular details following upon the ambassador's disappearance. So, it would seem that you and I are allies for this once, and the problem is already solved. There merely remains the task of finding and releasing the ambassador."
Mr. Grimm sat perfectly still.
"And why," he asked slowly, "are you here now?"
"For the same reason that you are here," she replied readily, "to see for myself if the—the person who twice came here at night—once for the ambassador's letters and once for his cigarettes—would, by any chance, make another trip. I knew you were here, of course."