Frank and Jack stood to their posts, ready and eager for the word that would send one of the steel engines of destruction speeding into the hull of the enemy.

There was not a man aboard who did not realize that they were indeed in a ticklish situation; for, besides the danger that always attended such an undertaking, there was the additional danger now of encountering one or more of the German under-water boats.

Nor was there a chance of a surprise attack. Lord Hastings was well aware that the presence of a hostile submarine had been flashed to every German battleship in the harbor.

Above, the sea was being swept with powerful searchlights, while below the under-sea craft of the Germans were dashing hither and thither in a vain endeavor to find some trace of the enemy who had so brazenly dared to enter what the Germans believed an impenetrable base.

Lord Hastings now turned to Jack with a command:

“You may come to the surface, Mr. Templeton.”

Jack repeated the command with alacrity; and when the D-17 had risen so that her periscope barely protruded above the top of the water, she was kept stationary.

“What do you see, sir?” asked Frank of Lord Hastings, who now peered intently into the periscope.

“German battleship half a mile to port and another half a mile astern,” was the reply. “The others are too far away for us, although they might reach us with a shell if their lights should happen to pick us up. We’ll make for the fellow to port and trust to luck that we get near enough without being spotted.”

He gave the necessary directions to Frank, who had taken the wheel.