The two shells which they carried were placed in proper position and they hurried back to the Holland.
They had scarcely re-entered the submarine craft when the dynamite shells went off.
The water was filled with the shattered rocks and as these cleared away they saw a good-sized opening ahead.
"Hurrah, for our imprisonment is at an end!" cried Andy.
The new Holland was sent forward at full speed through the opening, and once she was free those on board lost no time in quitting the vicinity of the islands.
"No more ocean cave for me," said Oscar. "One such experience is enough for me."
"And that serpent!" said Andy, with a shudder. "I imagine I'll dream of him for many a night to come." And he did, getting such a nightmare that Oscar often had to wake him up.
Four days later they came up to a point within twenty-two miles of Cape Nome.
The weather was now fine and a constant lookout was kept for foreign ships.
Once they passed an American warship bound for Seattle, and hailed her for news.