that sent Duvall headlong from the room.
He fully realized that the noise of the encounter, the shrieks of his
assailant, would quickly bring the other inmates of the house to the
room. He had no wish to be discovered there--his entrance had been too
irregular, too illegal, for that. With extraordinary rapidity he flung
himself through the window and without waiting to observe the results of
his intrusion, sped swiftly across the roofs of the two buildings, up
the steps to the attic roof, and from there, by means of the ladder, to
the roof of the apartment building. The janitor sat where he had left
him, smoking a pipe. Duvall looked back. Lights were visible in the room
he had just left. He saw a figure, one that closely resembled Marcia
Ford, cross the lighted area of the window. There was a second figure
with her--smaller, shorter, he thought. Who--what was it that had
attacked him? He stood in a daze, unable to grasp the meaning of the
experience through which he had just passed.

The janitor took his pipe from his mouth and rose.

"Find what you were looking for?" he asked with a grin. Duvall shook his
head.

"No," he said. "Not exactly. But I'm on the track of it."

"Want the ladder any more?"

"No, not to-night." He assisted the man to draw it up to the roof.

A few moments later he had reached the sidewalk. He glanced at his
watch. It was just eight o'clock. As he walked toward the entrance of
the house at No. 162, the front door opened, and a woman came out.

Duvall quickened his pace, but the woman was also apparently in a great
hurry. She ran swiftly across the sidewalk, and sprang into a cab which
stood beside the curb. Duvall was able to get but a fleeting glance at
her, but that glance was enough to convince him that she was the
mysterious prisoner who had so neatly given him the slip while in the
cab the night before. He sprang forward with a cry, but before he had
come within ten feet of the cab, the vehicle dashed off and proceeded at
a rapid rate up the street.

A second cab came along at almost the same moment. Duvall hailed it, but
the driver shook his head, indicating that he had a fare. In a moment
the second cab had passed, apparently in hot pursuit of the first. There
were no other cabs in sight. With a growl of anger and annoyance Duvall
turned back to the door of No. 162.

Should he ring the bell and ask for Miss Ford? he wondered. Of what use
would it be, to request an interview? Yet