“Well,” replied Jack calmly.  “And now I wonder if you would explain a few things to me?”

“You are at liberty to ask,” smiled Davis.

“Then, how did you get here—­why did you venture here—­and what of your little private expedition?”

“Those,” said Davis, “are what I should call considerable questions.  However, I can see no harm in answering them, particularly as you will never be able to repeat what you hear now.  I came here in our submarine the U-16, which, by the way, I have rechristened The Vulture—­a suitable name, don’t you think?—­and I came here because I had business here.  Now, as to your other question.  Our little privateering expedition is progressing famously.  We have already sunk one British ship and secured a quantity of booty, which may have something to do with my presence in Ostend.”

“I see,” said Jack.

“And,” continued Davis boastingly, “I came in right under the noses of the Germans.  My submarine lies in the harbor at this moment.  I came ashore in the guise of a German officer.  I was not questioned, nor were you, I take it?”

His last words formed a question, and Frank answered.

“No, we were not questioned,” he said.

“I thought not.  Well, when I presently have finished my business—­which, by the way, has been increased since your arrival—­I shall make my way back to my vessel and put to sea again.  I shall bother none of the Germans nor any ships of war unless they bother me—­my business is with ships of commerce, where there is booty to be had—­and when I have reaped enough I shall go to America, where I shall live the life a gentleman should.”

“You’ll make a fine gentleman,” said Jack sarcastically.

“You think so?” said Davis, apparently unruffled.  “So do I. But time presses.  I am sorry I can entertain you no longer.  You will please precede me from this room and upstairs.”

He arose, and with one revolver, motioned the lads out the door.  There was nothing for it but to comply; for both lads realized that while they might have jumped Davis, one of them probably would be shot down; nor was it for his own sake that each hesitated.

They preceded Davis up the stairs and into a large unfurnished room.  As he entered, Jack looked toward the window.  It was heavily barred and the walls of the room, he saw, were very thick.  Once locked in that room, the lad realized, there was little hope of escape.

“Now,” said Davis, “please cross the room and stand with your backs to me.  I shall leave you here to amuse yourselves.  You will have lots of time, for, I venture to say, the room will not be entered for months to come—­not until I return, which may not be for months.  Then I shall give myself the pleasure of calling on you.  Now, good-bye.  Turn and face the wall, please.”

Jack realized that it was now or never and he took a sudden decision.

“Face the wall, Frank,” he commanded quietly.  “It’s no use.”