ton for the key
to the apartment.

Now the question seemed in a fair way to being answered for him. The
fact that this girl's room was located so near to the Mortons' apartment
could not be a mere coincidence. There must be, between her room and the
Morton flat some means of communication, although of what nature he
could not now surmise. Fully convinced, however, that he might very soon
find out, he hurried up to Fifty-seventh Street and walked along until
he reached No. 162.

The house was, like that which immediately adjoined the apartment
building, an old-fashioned one, of brown stone, with a high front stoop.
It presented an appearance which, if not exactly dilapidated, was yet in
strong contrast to the neat appearance of its neighbors. A printed card
in one of the lower front windows indicated that roomers were wanted.

It was just the sort of place that Duvall had expected to find--just the
sort of place in which a working girl like Marcia Ford would live.
Located in a very excellent neighborhood, surrounded by apartment
buildings and houses of the best type, it still could afford to rent
rooms at the moderate figure that one of her class could pay. He went up
the front steps and rang the bell. "Is Miss Ford in? Miss Marcia Ford?"
he asked.

The servant who came to the door, a neatly dressed German girl, shook
her head.

"No, Miss Ford is not in. She usually gets back about half past six."

Duvall glanced at his watch. It was not yet three o'clock. He realized
that he had a long wait before him.

"Will you leave any message?" the girl asked.

"No. It is not important. I will come back." Descending the steps he
walked slowly in the direction of the apartment building, two doors
away.

Entering, he made his way to Mrs. Morton's apartment. The place was just
as they had left it, two days before. The windows had all been tightly
closed and fastened, and there were no further mysterious messages lying
about. Once more Duvall went to Ruth Morton's room, and opening the two
windows looked out.

His investigations, however, told him no more than he had learned
before. The three dormer windows in the home next door gazed vacantly
down at him, their windows covered with cobwebs and dust. The
impossibility of anyone making their way from even the nearest of them,
to the window where he stood, was manifest. And that a long rod or pole
could have been utilized to introduce the letters into the girl's room
was ev