“I would die of humiliation, to have that read before all these people,” murmured the young woman.

Lieutenant Commander Kimball gave Jack Benson a covert elbow-dig in the ribs, a move said, as plainly as words: 

“The joke is on you.”

Jack, however, through half open eyes, had been watching on his own account.  Suddenly he made a dive forward, shooting his hands down close to Miss Peddensen’s well-booted feet.

“That same old ship-rat!” exclaimed the submarine boy.  “I’ll catch the beast before he goes under your skirts, Miss Peddensen.”

At the mention of a rat so dangerously close young woman almost shot out of her seat in anxiety to get away.

As she bounded something dropped down out of the wide right sleeve of her coat.  It was a small memorandum book.

This was just what Jack Benson caught, in place of the pretended rat.  Moreover, the young skipper was clever enough to catch the book so that it fell into his hands open.

“It wasn’t a rat, after all, Miss Peddensen,” smiled Jack, straightening up and holding the open memorandum book so that both he and Kimball could see what was traced on the two pages that lay exposed.

There were sketches of the compressors, sketches of the mechanism by which the compressed air was forced into the tanks to drive the water out—­in fact, sketches of many vital features in the control of the boat.  Nor was more than a glance needed to make it plain that this young woman artist possessed expert knowledge of machinery.

At the cry of “rat” three or four women jumped from their seats.  The one nearest Miss Peddensen moved hastily to the forward end of the cabin.

“My dear young woman,” murmured the lieutenant commander, dropping into the vacated seat beside the Swedish girl, “you won’t mind, will you, if I keep these little matters to look over at my convenience!”

There was something so compelling in the look that flashed briefly in the naval officer’s eyes that Miss Peddensen lost color, and stammered: 

“No-o-o, certainly not; if such silly things interest you.”

“They interest me very much indeed,” murmured Kimball, thrusting “composition” and sketches inside his blouse.

As the naval officer plainly intended to remain where he was, Jack Benson turned, sauntering forward.

“Another spy nailed, beyond a single doubt,” muttered the young submarine commander.  “Will there never be an end to them.”

As Captain Jack glanced at the young Englishman, Drummond by name, he saw an unmistakable flash of hostility in the Englishman’s eyes.

“So you’re a spy, too?” quivered Benson, inwardly, turning on his heel.  After that, howsoever, the submarine boy took good care to keep Drummond under covert watch.

In time the “Benson” returned to the surface, being now much nearer land then when the aft had made its dive.  A few minutes later the boat ran into the harbor and made fast at its moorings.