ably, by some act or word, she will lead us to the prince,"
declared Mr. Grimm, "and the moment he is known to us everything becomes
plain sailing. We know she _is_ a secret agent--I expected a denial, but
she was quite frank about it. And I had no intention whatever of placing
her under arrest. I knew some one was in the adjoining room because of a
slight noise in there, and I knew she knew it. She raised her voice a
little, obviously for the benefit of whoever was there. From that point
everything I said and did was to compel that person, whoever it was, to
show himself."

His chief nodded, understandingly. Mr. Grimm was silent for a little,
then went on:

"The last possibility in my mind at that moment," he confessed, "was
that the person in there was the man who shot Senor Alvarez. Frankly I
had half an idea that--that it might be the prince in person." Suddenly
his mood changed: "And now our lady of mystery may come and go as she
likes because I know, even if a dozen of our men have ransacked
Washington in vain for the prince, she will inevitably lead us to him.
And that reminds me: I should like to borrow Blair, and Hastings, and
Johnson. Please plant them so they may keep constant watch on Miss
Thorne. Let them report to you, and, wherever I am, I will reach you
over the 'phone."

"By the way, what was in that sealed packet that was taken from Senor
Alvarez?" Campbell inquired curiously.

"It had something to do with some railroad franchises," responded Mr.
Grimm as he rose. "I sealed it again and returned it to the senor.
Evidently it was not what Signor Petrozinni expected to find--in fact,
he admitted it wasn't what he was looking for."

For a little while the two men gazed thoughtfully, each into the eyes of
the other, then Mr. Grimm entered his private office where he sat for an
hour with his immaculate boots on his desk, thinking. A world-war--he
had been thrust forward by his government to prevent it--subtle
blue-gray eyes--his Highness, Prince Benedetto d'Abruzzi--a haunting
smile and scarlet lips.

At about the moment he rose to go out, Miss Thorne, closely veiled, left
the Venezuelan legation and walked rapidly down the street to a corner,
where, without a word, she entered a waiting automobile. The wheels spun
and the car leaped forward. For a mile or more it wound aimlessly in and
out, occasionally bisecting its own path; finally Miss Thorne leaned
forward and touched the chauffeur on the arm.