the _Clara_ and stepped ashore. He
was neatly dressed, with a handsome face and alert figure. Lieutenant
Carstens bowed to him as he approached the place where he stood and
pointed to the prisoners.

"Do you know who that is?" whispered Ned to the sailor.

"No," was the reply, "except that he is the son of a prominent
politician in the United States."

Ned did not need to ask another question then. Jimmie had described the
senator's son, and Ned knew that the young man who had held possession
of the treaty box was there, in conference with the Lieutenant.

"I guess," the boy mused, "they've got the top hand. The Lieutenant has
his military authority, and also has the senator's son here to swear to
anything he asks him to!"

"You should have made a getaway in the _Manhattan_," Ben said, in a
moment.

"Then I wouldn't have seen the unloading of the arms," Ned answered.

Ben arose and stood yawning by the side of his prisoner. The Lieutenant
and the senator's son approached and stood for a moment looking down on
the two captives.

"Why not call the drum-head now?" asked the senator's son. "It will help
to pass a couple of hours which might otherwise be dull."

"Call it, then," said the officer. "The sooner it is over the better."

Ned looked up to the mountain as one looks to a friend for assistance
and cheer when things are going hard, and the mountain did not
disappoint him. For there, high up, was the green light of a distant
rocket.

The _Manhattan_ had found the gunboat and was using the signals.

CHAPTER XVIII.

THE MAN BEHIND THE DOOR.

It was a second later that the puff of the exploding rocket reached the
ears of those gathered about the boxes on the island, for sound does not
travel as rapidly as light. When it came, Lieutenant Carstens made a
dash for the side of the mountain and began the ascent. After ten
anxious minutes he was back again with a malevolent grin on his face.

"The gunboat has captured the _Manhattan_," he said, facing Ned.

Ned made no reply, for he was not a little puzzled at the remark. It
indicated that the speaker believed that he had as complete control over
the actions of those on the gunboat as he had over the conduct of those
on board the _Clara_ and the _Martha_. If this was true, there was
nothing more to hope for. The gunboat would bring Pat, Jack, and Jimmie
back as prisoners, and the drum-head would deal with five prisoners
instead of two.

The Lieuten