Frank and others of the ship's officers darted hither and yon, making sure that everything was in readiness. At the guns, the gunners grinned cheerfully. Frank approached the battery in the forward turret.

"All right?" he asked.

"O.K., sir," replied the officer in command of the gun crew. "Show us a submarine, that's all we ask."

"There are probably a dozen or so about here some place," returned Frank.

"Keep your eyes peeled and don't wait an order to fire if you see anything that looks like one."

"Right, sir."

The officer turned to his men with a sharp command.

Frank continued his inspection of the ship as the Brigadier dashed toward the vessel in distress, probably ten miles ahead.

Every man aboard the Brigadier was on the alert as the destroyer plowed swiftly through the water. It was possible, of course, that the submarines had made off after attacking the vessel, but there was always the possibility that some were still lurking in the neighborhood.

"Can't be too careful," Jack told himself.

Fifteen minutes later, the lookout was able to make out more clearly the ship ahead of them.

"Steamer Hazelton," he called to the quartermaster, who reported to Jack.

"Same vessel that sent the wireless, Frank," was Jack's comment. "We will have to look sharp. It's more than an even bet that some of those undersea sharks are watching for a ship to come to the rescue so they can have a shot at her also."

"We're ready for 'em," said Frank significantly.

"All right," said Jack. "In the meantime we'll stand by the Hazelton and see if we can lend a hand."

As the Brigadier drew closer those on deck could see signs of confusion aboard the Hazelton. Then there arose a large cloud of smoke that for a moment hid the Hazelton from view. This was followed by a loud explosion.

When the smoke cleared away, the water nearby was filled with struggling figures.

"Lower the boats," shouted Jack.

Instantly men sprang to obey the command, while others of the British tars still stood quietly behind their guns, their eyes scanning the sea.

Aboard the Hazelton, the crew, or what remained of the crew, were attempting to lower lifeboats. Directly one was lowered safely, and loaded to the guards with human freight. A second and a third were lowered safely, and put off toward the Brigadier.

In the meantime, lifeboats from the destroyer had darted in among the struggling figures and willing hands were lifting the victims to safety.

Then these, in turn, started back to the destroyer.

"I guess they're all off," said Frank to Jack.

"I hope so," was Jack's reply. "If I am not mistaken, there are women among the survivors."

"By George! I thought I saw some myself," was Frank's answer.

Suddenly there was a crash as the forward turret guns aboard the Brigadier burst into action. Looking ahead, Jack gave a startled cry, and no wonder.

For, from beneath the water, appeared a periscope and then the long low outline of a German submarine came into view.

Again the Brigadier's guns crashed, but the shells did not strike home.

Before the destroyer could fire again, a gun appeared as if by magic on the submarine's deck, and a hail of bullets was poured into the first of the nearby lifeboats. At the same time the U-Boat launched a torpedo at the Brigadier.

Jack gave a cry of horror at the predicament of those in the small boats.

But he did not lose his head, and at the same time maneuvered his ship out of the path of the torpedo.

Came a hail from the lookout aft.

"Submarine off the stern, sir!"

At the same moment the battery in the Brigadier's turret aft burst into action.

"Forward with you, Mr. Chadwick," cried Jack, "and see if you can't get better results there. The men seem to have lost their nerve."

Frank sprang forward. Jack's words were true. It appeared that the crew in the forward turret were so anxious to sink the first submarine that they had not taken time to find the range.

"Cease firing!" shouted Frank as he sprang into the turret.

The order was obeyed, but there came a grumble from the men at what they deemed such a strange command under the circumstances.

"I thought you fellows were gunners," said Frank angrily. "Smith, get the range."

Smith did so, and announced it a moment later.

"Now," said Frank, "get your aim, men."

No longer was there confusion in the forward turret. The guns were trained carefully.

"Ready," cried Frank. "Fire!"

"Crash!"

A moment and there was a loud cheer from the crew. The German submarine seemed to leap high from the water, and then fell back in a dozen pieces.

Frank wasted no further time on the first submarine. Leaving the forward turret, he dashed aft to where other guns were firing on the second submarine. Meantime Jack, perfectly cool on the bridge, had maneuvered his vessel out of the way of several torpedoes from the second U-Boat. But, as he very well knew, this combat must be brought to a quick end or one of the torpedoes was likely to find its mark.

From the deck of the second submarine, a hail of fire from a machine gun was still being poured into the helpless lifeboats. What execution had been done Jack had no means of telling at the moment, but he knew there must have been some casualties.

"The brutes!" he muttered.

The duel between the submarine and the destroyer still raged. It appeared that the commander of the submarine was a capable officer, for he had succeeded in keeping his vessel from being struck by a shell from the Brigadier.

In the aft turret of the Brigadier the British tars were sweating and muttering imprecations at their inability to put a shell aboard the enemy.

"Here," said Frank, "let me get at that gun."

The crew stepped aside and the lad sighted the weapon himself. Then he fired.