Soon after the naval men had taken their train for Washington, David Pollard came into Mr. Farnum’s office, carrying a valise and a brief case and announced that he was going away for a time where he could not be reached to rest and study and think.

It was the third day after this that Jack, wishing to see Mr. Farnum in regard to some supplies for the “Pollard,” went to his office.

“He’s not been here since three o’clock yesterday,” said his stenographer.

“Out of town?” asked Jack.

“I wish I knew.”

Jack called up Mr. Farnum’s house and got his wife on the telephone.  To his question she replied: 

“I got a note last night not to worry if he was late getting home.  But he has not come in yet,” and her voice had a catch in it.

Jack and his chums were greatly worried.  Had Melville played some trick on the boatbuilder?

“I’m going ashore,” said Eph the next morning, as soon as he had eaten his breakfast in the submarine cabin.

“For anything especial?” asked Jack.

“First, I want to know if anything’s yet known of Mr. Farnum.  Then, you know that Don Melville’s in town.  Why?  His father’s left and all the pounding workmen at his fake yard are gone, too.  Something needs explaining.”

“He’s trying to find out whom he can bribe into saying we set fire to the yard,” said Hal bitterly.

“Oh, on second thought Melville would conclude that would be too risky to do,” observed Jack.

“Maybe—­maybe not.  I’m going over to look about and listen.”

In less than an hour Eph Somers, agog with excitement, was back on the “Pollard.”

“Say, fellows, that Potter fellow that got into Mr. Pollard’s room and stole the papers broke jail last night.  Now we know what Don Melville was here for!  He had a hand in that!”

So far, the young fellow had refused to talk.

“Bribed by the Melvilles,” Hal had declared.  “But they’ll find that expensive, for he’ll continue to bleed them, now he knows how.”

Jack, who usually reserved judgment until he knew some facts on which to build, was inclined this time to agree with Eph, and Hal was certain that Somers was right.

“It would be to their advantage to have Potter disappear before they begin their dirty work against Mr. Farnum,” Hal insisted.

“I telephoned to Mrs. Farnum and she reports ‘nothing new,’” continued Eph.  “It’s queer.”

Just then the boys heard a hail and saw David Pollard, bag and brief case in hand, on the shore signaling to them.

“Where’s Farnum?” he asked as soon as he was on the submarine.

“We’d, any of us, give six months’ salary to know that, Mr. Pollard,” said Jack, and went on to tell what had been taking place.

“That spells ruin for us,” groaned the inventor, who knew how things stood financially.

“Do you think, Mr. Pollard, that we’d better suggest to Mrs. Farnum to put a detective on her husband’s trail?” asked Eph.