aph of Madeline Spencer.

"Sure thing!" she exclaimed. "That's she, all right. How in the world
did you ever--pardon me, Mr. Harleston, I shouldn't have said that."

"You're not meddling, Miss Williams. But it's a long story--too long to
detail now. Some day soon I'll confide in you, for you've helped me very
much in this matter and deserve to know. In fact, you've helped me more
than you can imagine. Meanwhile mum's the word, remember."

"Mum, it is, Mr. Harleston," she replied, "For once a telephone girl
won't leak, even to her best friends."

"I believe you," Harleston returned. "Keep your eyes open, also your
_ears_, and report to me anything of interest as to our affair."

Miss Williams answered with a knowing nod and an intimate little smile,
then swung around to answer a call. Harleston returned to his rooms. The
happenings of the recent evening were quite intelligible to him now:

When the episode of the cab of the sleeping horse occurred, Mrs. Spencer
was in the Chartrand apartment. Marston, in some way, had learned of
Harleston's participation in the cab matter, and with Sparrow had
followed him to the Collingwood, entering by the fire-escape--with the
results already seen. The noise on the fire-escape was undoubtedly made
by them, and the long interval that elapsed before they entered his
apartment was consumed in reporting to her, or in locating his number.

One thing, however, was not clear: how they had learned so promptly of
Harleston's part in the affair, and that it was he who had taken the
letter from the cab. Either someone had seen him at the cab and had
babbled to the Marston crowd, or else Mrs. Winton or Mrs. Clephane had
not been quite frank in her story. He instantly relieved Mrs. Clephane
of culpability; Mrs. Winton did not count with him. Moreover, it was no
longer of any moment--since Spencer's people knew and had acted on their
knowledge, and were still acting on it--and were still without the
letter. The important thing to Harleston was that it had served to
disclose what promised to be a most serious matter to this country, and
which, but for the trifling incident of the cab, would likely have gone
through successfully--and America been irretrievably injured.

Madeline Spencer had assured him that the United States was not
concerned; that the matter had to do only with a phase of the Balkan
question. But such assurances were worthless and given only to deceive,
and, further, were so