er the
matter of no consequence, for he paid not the slightest attention.
Instead he went straight to a cage beside the pigeon-cote, wherein a
dozen or more birds were imprisoned, removed one of them, attached a
strip of the tissue-paper to its leg, and allowed it to rise from
his out-stretched hand.

The pigeon darted away at an angle, up, up, until it grew indistinct
against the void, then swung widely in a semicircle, hovered
uncertainly for an instant, and flashed off to the west, straight as
an arrow flies. Mr. Wynne watched it thoughtfully until it had
disappeared; and Claflin's interest was so intense that he forgot the
necessity of screening himself, the result being that when he turned
again toward Mr. Wynne he found that young man gazing at him.

Mr. Wynne even nodded in a friendly sort of way as he attached the
second strip of tissue to the leg of another bird. This rose, as the
other had done, and sped away toward the west.

"It may be worth your while to know, Mr. Claflin," Mr. Wynne remarked
easily to the detective on the other house, "that if you ever put
your foot on this roof to intercept any message which may come to me
I shall shoot you."

Then he turned and went down the stairs again, closing and locking
the trap in the roof behind him. He should get an answer to those
questions in two hours, three hours at the most. If there was no
answer within that time he would despatch more birds, and _then_, if
no answer came, then--_then_--Mr. Wynne sat down and carefully
perused the newspaper story again.

At just about that moment the attention of one John Sutton, another
of the watchful Mr. Birnes' men, on duty in Thirty-seventh Street,
was attracted to a woman who had turned in from Park Avenue, and was
coming rapidly toward him, on the opposite side of the street. She
was young, with the elasticity of perfect health in her step; and
closely veiled. She wore a blue tailor-made gown, with hat to match;
and recalcitrant strands of hair gleamed a golden brown.

"By George!" exclaimed the detective. "It's her!"

By which he meant that the mysterious young woman of the cab, whose
description had been drilled into him by Mr. Birnes, had at last
reappeared. He lounged along the street, watching her with keen
interest, fixing her every detail in his mind. She did not hesitate,
she glanced neither to right nor left, but went straight to the house
occupied by Mr. Wynne, and rang the bell. A moment