With fast beating hearts they dashed on and a few minutes later stood on the edge of the mastmarked abyss, gazing downward into it.

As they did so a shout—such a shout as had never disturbed the great silences of that region—rent the air—

"The Viking ship at last. Hurray!"

The gully was about thirty feet deep and at the bottom of it, glazed with the thick ice that covered it, lay a queerly formed ship with a high prow,—carved like a raven's head.

IT WAS THE VIKING SHIP.

After all the centuries that had elapsed since she went adrift she was at last found, and to be ransacked of the treasure her dead sailors had amassed.

The first flush of the excitement over the discovery quickly passed and the boys grew serious. The problem of how to blast the precious derelict out of the glassy coat of ice without sinking her was a serious one. Frank, after a brief survey, concluded, however, that the ice "cradle" about her hull was sufficiently thick to hold her steady while they blasted a way from above to her decks and hold.

It was useless to linger there, as they had not brought the needful apparatus with them, so they at once started back for the Golden Eagle. Frank's first care, arrived once more at the aeroplane, was to send out the good news, and it was received with "wireless acclaim" by those at Camp Hazzard.

"Will be there in two days by motor-sledge. Commence operations at once," was the order that was flashed back after congratulations had been extended. As it was too late to do anything more that night, the boys decided to commence work on the derelict in the morning. After a hearty supper they retired to bed in the chassis of the aeroplane, all as tired out as it is possible for healthy boys to be. Nevertheless, Frank, who always—as he put it—"slept with one eye open," was awakened at about midnight by a repetition of the noise of the mysterious airship.

There was no mistaking it. It was the same droning "burr" they had heard on the night following their discovery of the flaming mountain. Waking Harry, the two lads peered upward and saw the stars blotted out as the shadowy form of the air-ship passed above them—between the sky and themselves. All at once a bright ray of light shot downward and, after shifting about over the frozen surface for a time, it suddenly glared full on to the boys' camp.