th my key and we'll
soon find out."

"Perhaps we would better retire to the cabin," suggested Captain Curtis,
noting the curious faces gathering about. "We can settle the whole
matter there."

Lieutenant Carstens would not have entered the cabin if one of the
officers of the gunboat had not crowded him down the stairway.

"This is an outrage!" he shouted.

The senator's son now came hastily down the steps, his face red with
rage, his fingers working convulsively, as if already playing about the
throat of an enemy.

"That box is mine!" he cried. "I demand that it be returned to me
unopened. I am the son of a United States senator."

"If what I suspect is true," Ned said, "you will need all the political
pull a member of the senate has in order to keep yourself out of the
penitentiary."

"Put that boy out of this cabin!" snarled the young man. "This is my
private room. I paid for its use during the cruise."

Ned whispered a few words to the Captain, and the latter turned with a
smile to a door opening at the rear of the little room where the excited
group stood.

"Well," he said, "there is a question here as to whether the box
contains any treasonable documents. If the box belongs to you, open it
and we'll see if the charge is true or false. If it is false the box
shall be returned to you."

"I have lost my key," was the reply.

"How long ago?" asked Ned.

The young man turned a supercilious face on the boy, but answered:

"Several days ago. What is it to you?"

"Where were you when you first missed it?" Ned persisted.

"That does not concern you," was the reply.

"If you lost it in Captain Godwin's station," Ned said, with a smile, "I
presume I have it."

He held up the key he had found on the river bank, among the bushes, on
the morning following the abduction of Lieutenant Rowe, and the other
lunged for it.

"Never mind!" Ned laughed, dodging away, "I don't care to part with the
key just now. After the investigation of the box is over you may have
it."

"Unlock the box," ordered the Captain.

Ned stepped forward with his key, but was brought to a stop by a beating
on the door of the rear cabin.

"I forgot," the boy said, "and the man in there doubtless desires his
liberty. If some of you will unlock the door you will find the man the
government sent away in charge of this expedition."

"What do you mean?" asked the Captain, while Carstens sank back in his
chair with a groan.

"I think,"