"By Jove! What a murderous scoundrel!" muttered Frank.

Jack nodded.

"No worse than the rest of them, I'll wager," he said. "But, hello! The Ventura's moving again."

As soon as Jack had left the deck of the steamer, Captain Griswold had ordered the engines started and prepared for a quick dash to shore.

"There are likely to be more of those pesky submarines about here," he muttered, "and the sooner I reach port the better."

Accordingly he ordered full speed ahead.

"Do you know," said Frank, "I've a hunch that the U-87 is not through with the Ventura. You know how the German is. He doesn't like to admit he's been licked, so I figure the submarine commander is likely to have gone ahead and will be awaiting the approach of the Ventura."

"Now by George! I wouldn't be a bit surprised," Jack agreed. "Well, we'll be ready for him."

"What are you going to do, Jack?"

"I'll show you. Come."

Jack dashed to the radio room, Frank at his heels.

"Get the Ventura for me," Jack instructed the operator.

It was perhaps five minutes later that the Ventura answered the call. Jack took the key.

"Captain Griswold?" he asked.

"Yes. Who are you?"

"Captain Templeton, destroyer Essex."

"Well, what do you want this time?"

"Slow down. I'm coming aboard again."

"What for?"

"I'll explain when I get there."

"All right, but I'll tell you I don't like this business."

The instrument became silent.

"Now tell me what you're going to do, Jack," said Frank, as he followed his chum and commander on deck.

"It's very simple," said Jack. "As you have said, I believe that the submarine commander will intercept the Ventura again farther along toward the shore. Now, I'm going to turn the Essex over to you temporarily and go aboard the Ventura. You know the Germans as well as I do. This man will no more think of sinking the Ventura without doing a bit of bragging to the captain, who fooled him once, than he will of flying."

"That's true enough," Frank admitted.

"All right. Now I'll be aboard when he gets there. If he comes aboard, I'll grab him there. If he doesn't I'll jump to the deck of the submarine after him and tumble him overboard. I'll trust to you to keep the submarine occupied and to get a boat to me."

"It's a desperate venture, Jack," Frank protested.

"So it is," was Jack's reply, "but I've a longing to capture this fellow.

If we just sink the submarine, I can't do it of course. Another thing, it may be that I am not doing just right in leaving my ship, but it will only be for a couple of hours and I know you can handle it as well as I can."

"Oh, I won't sink her," grinned Frank. "But why not let me be the one to go?"

"Because I'm not sure you can handle the German commander."

"But you're sure you can, eh?"

"He'll have to be something new in the line of a German if I can't."

"All right," said Frank. "Have it your own way. You're boss here, you know."

Meantime the Essex and the Ventura had been drawing closer together.

Directly a boat put off from the destroyer and ran alongside of the steamer. Jack clambered over the side and the launch returned to the destroyer.

Captain Griswold was waiting for Jack.

"Now what's up?" he wanted to know.

"Come to your cabin and I'll explain," said Jack.

In the seclusion of the cabin he outlined the situation. When he had concluded a sketch of his plans, Captain Griswold demurred.

"But I don't like to risk my passengers," he said.

"You won't be risking them any more with me aboard than you will without me," Jack explained. "Besides, you will have the additional protection of the destroyer. In fact, it may be that the presence of the Essex will scare the submarine off, but I doubt it. The German commander, as all of his ilk, is angry at having been balked of his prey. He'll probably have one more try, destroyer or no destroyer."

"Well," said Captain Griswold, "you're a British naval officer and should know something, whether you do or not. But I'll tell you right now I hope the submarine doesn't show up again."

Nevertheless, Captain Griswold was doomed to disappointment, for the U-87 did reappear.

It was almost 6 o'clock in the evening when all on board were startled by a cry from the lookout.

"Submarine on the port bow, sir."

Instantly all became confusion on the big merchant ship. Passengers, of whom there were perhaps fifty, became greatly excited. Every man on board strapped on a life preserver, and waited for he knew not what.

The fact that, directly astern, the Essex, British destroyer, was in plain sight and trailing them, did not allay their fears. Came a shot from a gun mounted forward on the submarine, a signal to heave to.

"Obey it," said Jack, to Captain Griswold, on the bridge.

Captain Griswold ordered his engines stopped.

"I'll keep out of sight for a moment," said Jack. "The commander may come on board."