opposite side. The three watched the illumination with absorbing
interest for a moment.

"Hans must be up there," Ned, muttered, "although I would almost as soon
expect to find him up in a balloon."

"I reckon you'll find an owl with wise eyes and feathers up there, if
you wait," said the officer, with a smile. "The boy you refer to never
could have traveled here alone."

"You just wait," advised Jimmie.

Presently the mist of light centered down to three small flames,
apparently coming from three narrow twists of paper, burning in a row in
front of a window on the second floor. Jimmie grasped Ned's arm as the
three tiny columns of flame showed for an instant and then vanished.

"There!" he said. "Do you know what that means?"

"It is a warning of danger," Ned muttered.

"Say that again," exclaimed the officer. "What kind of a game is this?"

"It is a Boy Scout warning," Ned replied. "In the forest three columns
of smoke express the warning. How did this German boy learn all this?"
he continued, turning to Jimmie.

"Don't you ever think the Philadelphia Boy Scouts are slow!" answered
the boy. "Hans has been out in the forest with them, and knows all
about woods work, an' signs, an' signals. Give it up, now?"

"Yes," replied the officer, "I give it up. You boys must have a
wonderful organization."

"We certainly have," Ned replied.

The three waited for a moment, but no more signals came from the window.
Instead a heavy footfall sounded outside the door and a man they had not
seen before stepped into the room.

He was a heavily built man, with broad shoulders, black hair and eyes,
and a wicked mouth. His face looked hard and repulsive, like the face
of a reckless, intolerant, whisky-drinking captain of police in a
graft-ridden district. He closed the door with his back as he entered.

"You are Ned Nestor?" he asked of the officer. The latter pointed
toward Ned.

"That child!" exclaimed the newcomer.

Jimmie restrained himself with an effort, for he knew that this was no
time to engage in a quarrel. He turned his back to the group and looked
out of the window into the court.

There was now no light at the window from which the warning had been
given, but there were flickers of uncertain candles at some of the
others. The hooting of the owl had undoubtedly attracted the attention
of the occupants of the building.

As Jimmie looked, however, the sash of the window he was watching was
p