Ruth's bedroom.

To his disappointment the two windows were not only closed and fastened,
but so tightly stuck on account of the fresh paint that it required the
combined efforts of the janitor and himself to open them. That they had
been opened, since the painting had been done, some ten days before, was
clearly out of the question. Duvall made up his mind at once that
however the person who had placed the mysterious message in Ruth's room
had effected his or her entrance, it had not been by way of the
apartment on the top floor.

Somewhat disappointed, he went to the floor below, and thanking the
janitor for his kindness, rejoined Mrs. Morton.

"What have you discovered, Mr. Duvall?" the latter asked, eagerly.

"Nothing, so far. I confess the thing is somewhat of a puzzle."

"Someone _must_ have been in Ruth's room."

"Not necessarily."

"But--why not?"

"You will remember that you found the letter on the floor. That would
seem to me to indicate rather the opposite. If anyone had actually been
_in_ the room, they would have been far more apt to place the message on
the dressing table. That it was found upon the floor indicates to my
mind that it was in some way inserted--thrown, perhaps--through the
window from without." He took the letter in question from his pocket,
and sitting down, gazed intently at the surface of the envelope.
Presently he passed it over to Mrs. Morton. "What do you make of that?"
he said, indicating with his finger a curious row of indentations,
extending in a semi-circular line about midway of one of the longer
edges of the envelope.

The marks were very faint, but by turning the letter about in the light,
Mrs. Morton at last managed to make them out. What they were, how they
had been placed there Duvall could not say. Yet their presence indicated
something of value, of that he felt sure.

"I don't understand them at all," Mrs. Morton replied, returning the
letter to him. "It looks as though someone had held the letter in a--a
pair of pincers."

The suggestion conveyed by her words interested Duvall greatly. The same
thought had been forming in his own mind.

He rose to his feet, his eyes shining with interest. Why could not such
a pair of pincers or forceps have been attached to a long pole, such as
a fishing rod, and the letter in this way pushed through the window and
released by pulling on a cord attached to one of the forceps' handles?
The thing was perfectly practical, exce