ven't even seen him."

"Very well. Now you may give the order to submerge and we'll make for
the rendezvous."

Jack obeyed.

It was just exactly three minutes to twelve when Lord Hastings, having
taken his bearings and found he was in the designated spot, gave the
command to come to the surface.

Slowly the U-16 arose from the deep, and immediately she rested upon the
surface, Jack and Frank followed Lord Hastings to the bridge.

The night was perfectly dark and at first they were unable to make out
an object upon the silent water. But suddenly, to the left, there was a
single brief flash of light; a second to the right; one forward and one
astern; then other arrivals from the deep flashed a signal of their safe
arrival. Producing his small pocket flashlight, Lord Hastings did the
same.

"Seven besides ourselves," he muttered to himself.

Slowly now the submarines drew closer together until presently a voice
from the bridge of one could be heard by all as Admiral Schuler
addressed his captains.

"We shall submerge until our periscopes alone show," he gave his orders.
"Then we shall proceed at full speed for the mouth of the Thames."

"But mines?" protested a voice.

"The mines have been swept clear," was the reply. "A flotilla of mine
sweepers have been busy since dark. Now, heed these orders: We shall
keep as close together as possible. Reaching the Thames, one submarine
must lead the way. I shall call for a volunteer."

"Here, sir," Lord Hastings spoke up before the other commanders had a
chance.

The others also volunteered, but Admiral Schuler awarded the honor to
the U-16.

"You spoke first," he explained. Then he continued: "Unfortunately, we
have been unable to learn the exact positions of the various British war
vessels in the Thames, but we do know that there are many stationed
there--just how far up the river I cannot say. However, once there we
shall not return until we have sunk them."

A subdued cheer ran across the water in the darkness.

"It is time to go," said Admiral Schuler. "I shall show the way to the
Thames, when the U-16 will take the lead. To your posts and follow me
closely."

He went below, and the other commanders did likewise. A moment later the
purr of machinery became audible aboard each vessel. Each submerged
until the tip of her periscope protruded above the water, and then they
sped after the flagship into the darkness of the night.

Swiftly they went, for Admiral