Schuler realized the value of haste. He
wished to make the raid and be out to sea again before the break of day.

Aboard the eight units of the submarine flotilla there was joy
unrestrained. The crews of each vessel had been taken into the
confidence of their commanders by this time and the men aboard seven of
the craft were eagerly awaiting the moment when they could strike a
terrible blow at the British navy. In view of the successes that had
already attended the efforts of the German submersibles, there was
little doubt in the hearts of the men that the present venture would be
accomplished.

Even the three British sailors aboard the U-16 were cheerful, for
although they did not realize the exact import of their mission, they
knew Lord Hastings well enough to realize that he was acting in this
manner only because there was some big duty to perform. They were
content to follow him blindly.

Perhaps the only four men with the fleet who did not really have their
interests aroused were Davis and his three fellow conspirators. Their
only hope was that the sooner they came through the venture successfully
the sooner they might get to work on their own plans.

The submarine fleet sped silently through the waters, going as swift as
the wind; and when it finally reached the broad mouth of the Thames, the
key to London itself, it still lacked two hours of dawn. But it was time
for quick work and Admiral Schuler was not the man to hesitate--had he
been, he would not have held this important post.

The submarines came to the surface now, in accordance with previous
instructions, and Admiral Schuler, by a signal with his light,
instructed the U-16 to proceed ahead. The other vessels dropped back a
little.

"Well," said Lord Hastings to Frank and Jack, who stood beside him on
the bridge, "here goes. May good fortune attend us."

He gave Jack the command:

"Full speed ahead!"

CHAPTER XX.

THE TRAP IS SPRUNG.

As the three officers aboard the U-16 knew, British battleships and
vessels of war of all descriptions had been stationed all along the
Thames, many of them patrolling the very mouth of the river. But now, as
Lord Hastings, Jack and Frank stood upon the bridge of the little
submarine after it had entered the mouth of Thames, there was not a
vessel of any kind to be seen in the darkness.

"Admiral Fischer's orders have been followed out, sir," said Jack in a
low voice.

Lord Hastings nodded but made n