ugh his previous examination had showed him
both the fact that the newly painted surface of the fire escape was
unmarred, and that the ladder at the lower floor was drawn up some nine
or ten feet from the ground. He felt certain that Miss Ford had not
reached Ruth's room in that way.

He glanced upward. The fire escaped stopped at the level of the floor
above. To ascend from it to the roof was impossible.

Remembering that the top apartment was vacant, Duvall re-entered the
building and hunting up the janitor, told him that he desired to get out
on the roof.

The man remembered him, from his first visit, and the inquiries he had
then made about the tenants of the apartment above.

"I am making some special inquiries on Mrs. Morton's behalf," he
explained. "You can go with me, if you like, to see that I do nothing I
shouldn't."

The janitor joined in his laugh.

"I'm not worrying," he rejoined, "but I'll go along, just the same, to
show you the way." He led the detective up one flight of stairs and,
going to the end of the outer hall, unlocked and opened a small door
beside the elevator shaft. A short spiral staircase was disclosed.

Snapping on an electric light, the man ascended the steps, and, after
fumbling for a moment with the catch, threw open a trapdoor leading to
the roof. In a moment both he and Duvall had climbed out upon the tiled
surface. Duvall went to the edge which overlooked the house adjoining,
and peered down. He at once saw something that interested him.

The house with the dormer windows consisted, as has been previously
mentioned, of four stories and an attic. Its roof rose several feet
above the level of the window of Ruth's room, which was on the fourth
floor of the apartment building. But Duvall saw at once that this
elevation of the adjoining house did not extend all the way back, but,
in fact, stopped a little beyond the point where it joined the
apartment. From here to the rear of the lot the building had no attic,
its rear extension being but four stories high. In this position on the
apartment-house roof, the roof of the back building was at least fifteen
feet below him.

Another thing that he noticed at once was the fact that the second
house, No. 162, was of almost the same design as the first, that is, it
consisted of a main building with an attic, and a rear extension,
reaching to the same level as that of the house between. It was clear
that if anyone living in the second hou