“Well, first, you know, Uncle Sam has some valuable seal islands in the Aleutian group.  Maybe, during the war the Japs or Russians have got careless about drifting around that way and carrying off a few hundred skins.  Might be, you know.

“But I’m not saying that’s it.  A sub would be a mighty fine craft for watching that sort of game, though.  And then, there’s another thing I’ve thought of.  There’s gold in Russia, on the Kamchatkan peninsula; you know that, don’t you?”

“No.”  Dave opened his eyes wide in surprise.

“Heaps of it.  Tons and tons!  Just waiting for the digging.  And before we went into the war, when Russia was still with the Allies and needed money, our Government, or independent capitalists, I don’t know which, furnished the Russians a lot of machinery for mining the gold; about a million dollars’ worth, I guess.  Then came the revolution in Russia.  I doubt if a cent has been realized from the sale of machinery.  Who’s in possession of that peninsula at the present time?  God alone knows.  Japan would like to meddle there, I’m sure.  Perhaps we’re being sent up there to conduct an investigation.

“Those are my two guesses.  Take ’em for what they’re worth.”

“You don’t think,” said Dave, “that we’d attempt the Pole?”

The ensign was silent for a time.  “No,” he said at last, “I don’t.  Of course, Stefansson has said that a ‘sub’ is the most practical way to go there; that ice-floes are never more than ten feet thick and twenty-five miles wide, and all that; but there are too many unsettled problems relating to such a trip.”

“But say!” exclaimed Dave, “who is this doctor of ours, anyway?”

“Blamed if I know,” said Blake, as he turned away to go below.

“Well, anyhow,” Dave remarked, “whoever he is, he’s going to take us where the white ice-floes are drifting.  Look at the color of this craft; blue-white, like the ice itself.”

The journey North, save for a storm, which they avoided by submerging, was uneventful until they found themselves in the company of scattered ice-cakes with the snow-capped ridges of the Aleutian Islands looming up before them.

In no time at all every man on the craft realized that on these islands was to be found one of the objects of their quest; for, once they had sighted the shores, the funnel was dropped, electric power applied, and watchers, dressed in white to match the color of the craft, set to scan the shores for signs of life.  They stole through the water like some ghost craft.

“Believe it’s that seal-fishery business?” asked Dave, as he and the ensign took their watch.

“No.”

Dave was certain from the tone that the doctor had confided his secret to the ensign.  He asked no more questions.

So they drifted on.  The wind had dropped.  The swell rolled their craft as it plowed along.  Here and there a sea-lion thrust its ugly head from the water.  Twice a seal attempted to climb upon the slippery hull for a rest, but, to the amusement of the boys, slid back into the water.  An offer to assist the third one was not appreciated, and the ridiculously human-like head disappeared beneath the water with great alacrity.