sound of an automobile
approaching, and soon they could distinguish its lights as it negotiated
the rough, winding woodland road that led to the house. A toot from the
horn as it arrived brought the men within the house tumbling out the
front door with huzzas of greeting for their leaders, and Fleck observed
that all the men as they came out automatically raised their hands
in salute.

"Ex-German soldiers, every one of them," he muttered.

As the Hoffs got out of the car a shaft of light from the opened front
door threw the figures of the new arrivals into sharp relief, and Jane
saw, with a shudder of terror, that Frederic was dressed in an aviator's
costume. There was no longer any doubt left in her mind that he was one
of those going to certain death, and a dry sob choked her.

The Hoffs passed within the house, and the door was closed.

"Now," cried Fleck, "to your stations, men. Each of you take a rifle.
You stay here, Miss Strong. Come on, Carter."

CHAPTER XVI

THE ATTACK ON THE HOUSE

In accordance with instructions already issued two of Fleck's men rushed
for the front of the house, where with rifles ready they stood guard,
while the others took cover in the shadow of one of the outbuildings a
few feet distant from the rear entrance.

Apparently the plotters had been so long undisturbed in their mountain
fastness that they had ceased to take even the most ordinary precautions
against surprise. So far as could be discovered they had posted no
guards over the aeroplanes and their deadly cargo, nor at either of the
two doors to the main building. Nevertheless Fleck, as he crept
stealthily up to the building with Carter at his side, took out his
automatic and held it in readiness, and Carter followed his example.

There was no moon to reveal their movements as they approached the rear
of the house. The evening was warm, and one of the windows had been left
open. Noiselessly they crept up to it and looked within. It opened into
a large room used as a dining hall, where they could see all of the men
clustered about one of the tables, at the head of which sat old Otto
Hoff with Frederic at his side. On the table before him was what
appeared to be a rough map or blueprint. Frederic and five of the other
men, Fleck observed, now wore aviation costumes.

"Comrades," old Otto was saying in German, "here is the course. You will
have no difficulty in following it. Down the river straight till you see
the lig