Then in “The Submarine Boys and the Spies” was shown how the young men successfully foiled the efforts of spies of foreign governments to learn the secrets of the Pollard craft.

In “The Submarine Boys’ Lightning Cruise” the adventures of these clever, enterprising boys were carried further.  In this book, was told how the boys were trained in the handling of the actual torpedo of, warfare.  The Pollard boats, “Benson” and “Hastings” were entered in official government tests in which the submarine craft of several other makes competed.  The desperate lengths to which the nearest rival of the Pollards went in order to win were told with startling accuracy.  The result of all these tests was that the Pollard company received from the Navy Department an order for eighteen submarine torpedo boats, the “Benson” and the “Hastings” being accepted as the first two boats on that order.

By the time the present narrative opens it was near the first of May.  Over at the shipyard, where facilities had been greatly increased, two of the submarines had lately been finished, and four more were under way in long construction sheds.  Work on the government’s order was being rushed as fast as could be done while keeping up the Pollard standards, of high-class work.

Of late Jack and his young friends, though their pay went on, had little work to do.  Whenever a new boat was completed it was the task of the submarine boys to take her out to sea and put her through all manner of tests in order to determine her fitness.  But there were days and days when the submarine boys had naught to do but enjoy themselves as their fancy dictated.

“Shall we sit down here?” asked Jack, as he and the tall German entered the hotel office.

Jabez Holt stood behind the desk, bent over the register, on which the Professor’s name had been the only new one in a week.  The old landlord pretended to be busy, but he was covertly watching and listening.

“Sit here?” repeated Professor Radberg.  “Ach, no!  Come along with me.”

There was something rather disagreeably commanding in the German’s invitation, but Jack merely smiled quietly as he followed in the stranger’s wake.  Up the stairs they went.  The Professor unlocked a door, admitting himself and his guest to the outer of a suite of two rooms.  Once they were inside Radberg locked the door behind them.

“Come to the other room, Herr Benson,” directed the Professor.  The door of this inner room the German also locked, remarking: 

“Now, if the man, Holt, chooses to follow and listen, he can hear nothing.”

“All this sounds mighty mysterious,” laughed Jack Benson, good-humoredly.

However, the submarine boy went and stood by a chair near the window and then waited until he saw that the stranger was about to seat himself.

“Now,” asked Jack, stretching his legs, “what’s the business about?  I haven’t a whole lot of time to-day.”