at beside
her.

"I think," Miss Thorne suggested tentatively, "that that accounts
perfectly for Monsieur Boissegur's disappearance."

"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 Boissegur," 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 Boissegur--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 Boissegur 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 Boissegur 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."

"You knew I was here," repeated Mr. Grimm musingly. "And, may I--?"

"Just as you knew that I, or some one, at least, had entered this house
a few minutes ago," she interrupted. "The automobile horn outsi