When the other passengers learned the nature of their mission many of them expressed the most intense interest in the two chums. More than one mature man declared he stood ready to take off his hat to such brave lads, and wished them all manner of good luck.

They sat up until a late hour, and were thrilled when it was learned that the vessel was even then being towed out from her berth into mid-stream by a fleet of powerful tugs. Even these usually noisy little monsters seemed to have their mufflers on, for they accomplished their work with but a fraction of the customary whistling and puffing and snorting.

The boys bundled up and went on deck to watch what took place. Leaving an American port during wartime was an entirely different thing from what it had been in other days. Silence and mystery had taken the place of whistle-blowing and music and loud salvos of cheers. Now the spectators stood and strained their eyes for a last look at those friends aboard the departing steamship, whom possibly they were fated never to see again in this world.

Tom and Jack stood on deck and looked back toward the overhead light that marked the torch in the hand of the Statue of Liberty. Long they stayed and paced the deck when chilled by the night air. Now and then they turned to look back to where the great city slept, secure, by reason of the vast ocean’s width, from aerial bombardments and guarded against attacks from hostile battleships by the eternal vigilance of the Allied fleet by which the Germans were bottled up in their home waters at Kiel.

Ahead of them lay the broad Atlantic. They were now headed for the danger zone. Presently they would come to that sector which the German high command had marked as the cruising ground for their insatiable submarine rovers. Behind each and every rolling billow might lie a concealed peril, but the hearts of those two chums felt no fear as they looked forward with confidence to the work to which they had dedicated their lives.

CHAPTER VI
NEARING THE BARRED ZONE

Some days passed.

The big steamer, headed toward her goal, which was a harbor in the south of England, kept pushing through the vast expanse of water. The boys would have preferred sailing on a French vessel, but at the time could secure no booking.

As Jack had said, “half a loaf is better than no bread;” and once across the Atlantic they would not have a great deal of trouble jumping over to France, since the Channel was so narrow that on clear days one could see the white chalk cliffs of Dover from the other side.

Nothing out of the way had happened so far on the voyage, but every one knew the critical days and nights were yet to come. The boys had made numerous acquaintances aboard, but, acting on the advice of Lieutenant Carson, they had spoken of their own affairs as little as possible.