For, despite all precautions taken by British naval authorities, enemy submarines more than once had crept through the channel, once penetrating Dover harbor itself, where they had wreaked considerable damage before being driven away by British destroyers and submarine chasers.

A few moments later Jack signaled the engine room.

"Half speed ahead."

Slowly the Brigadier slipped from her anchorage and moved through the still waters of the harbor. Directly she pushed her nose into the channel, then headed east.

"Full speed ahead!" Jack signaled the engine room.

The Brigadier leaped forward.

"Better turn in, Jack," said Frank. "It's Thompson's watch."

"No, I'll stick until we reach the Atlantic," returned Jack.

"Then I'll stick along," said Frank.

This they did.

It was hours later when the Brigadier ran clear of the channel and breasted the heavy swell of the Atlantic. Jack spoke to Thompson, the third officer.

"I'm going to turn in," he said. "If anything happens, call me at once."

"Very well, sir," was the third officer's reply.

He saluted briefly. Jack and Frank went below.

"Come in a moment before you turn in, if you wish," Jack said to Frank.

"May as well," replied the latter. "I don't feel like turning in for an hour yet."

"Well, you can't keep me out of bed that long," declared Jack. "I've got to be stirring before you go on watch again. But I thought we might talk a few moments."

Nevertheless, it was an hour later that Frank went to his own cabin. He turned in at once and was soon fast asleep.

On the other hand, sleep did not come to Jack so soon. For an hour or more he lay in his bunk, reviewing the events of the past and his responsibilities of the present.

"It's a big job I have now," he told himself. "I hope I can carry it through successfully."

But he didn't have the slightest doubt that he could. Jack's one best characteristic was absolute confidence in himself.

CHAPTER V

A RESCUE

H.M.S. Brigadier was steaming steadily along at a speed of twenty knots.

Jack himself held the bridge. Frank and Lieutenant Hetherton, who stood nearby, were discussing the sinking several days before of a large allied transport by a German submarine in the Irish sea.

"She was sunk without warning, the same as usual," said Hetherton.

"The Germans never give warning any more," replied Frank, "Of course, the reason is obvious enough. To give warning it would be necessary for the submarine to come to the surface, in which case the merchant ship might be able to place a shell aboard the U-Boat before she could submerge again.

So to take time to give warning would be a disadvantage to the submarine."

"At the same time," said Hetherton, "it's an act of barbarism to sink a big ship without giving passengers and crew a word of warning."

"Oh, I'm not defending the German system," declared Frank. "I am just giving you what I believe is the German viewpoint."

"Nevertheless," said Hetherton, "it's about time such activities were stopped."

"It certainly is. But it seems that the U-Boats are growing bolder each day."

"It wouldn't surprise me," declared Lieutenant Hetherton, "to hear almost any day that U-Boats had crossed the Atlantic to prey on shipping in American waters."

Frank looked at the second officer sharply. He was sure that Jack had not divulged the real reason for their present voyage, and he had said nothing about the matter himself.

"Just a chance remark, I guess," Frank told himself. Aloud he said: "I hardly think it will come to that."

"I hope not," replied Hetherton, "but you never can tell, you know."

"That's true enough, too," Frank agreed, "but at the same--"

He broke off suddenly as he caught the sharp hail of the forward lookout.

"Ship in distress off the port bow, sir," came the cry.

Jack was at once called to the deck.

Instantly Frank and Lieutenant Hetherton sprang to Jack's side. At almost the same moment the radio operator emerged from below on the run.

"Message, sir," he exclaimed, and thrust a piece of paper in Jack's hand.

Jack read it quickly. It ran like this:

"Merchant steamer Hazelton, eight thousand tons, New York to Liverpool with munitions and supplies, torpedoed by submarine. Sinking. Help."

"Did you get her position?" demanded Jack of the wireless operator.

"No, sir. The wireless failed before he could give it."

"Don't you think it may be the vessel ahead, sir?" asked Lieutenant Hetherton.

"Can't tell," was Jack's reply. "It may be, in which case there are probably more submarines about. Clear ship for action, Mr. Chadwick."

No sooner said than done.