“What I would like to know,” said Frank, “is why her commander, instead of trying to escape at once, didn’t launch a torpedo or two.  He might have disposed of one of us.”

“But the others would have surely done for him,” said Lord Hastings.  “He probably figured he could submerge before we could hit him.”

“He guessed wrong that time,” declared Frank.

“Rather,” agreed Jack with a smile.  “There is no use talking, Frank, you are some boy when it comes to shooting.”

All that afternoon the motorboat flotilla trailed the Glasgow; but until nightfall no other German submarine had appeared.  An hour after nightfall, Commander Thompson gave the command to put about and return.

Slowly the little craft came about and started back toward Bantry Bay.  Behind them now, the Glasgow, safe at last, steamed rapidly away, bound for the distant port of New York, and “home,” said Frank to Jack.

“Do you wish you were on her,” asked his chum curiously.

“No,” replied Frank, slowly, “unless I was sure I would find my father waiting for me when I reached there.  However, I am having a pretty good time on this side and I know that I shall return safely some day.”

The Hawk, last in line, made her way back slowly.

An hour after the lights of the Glasgow had faded from view, Frank, glancing forward, was unable to make out the distant light of a single of the other motorboats.  He called Lord Hastings’ attention to this fact.

“Is that so?” exclaimed his commander in some surprise.  “I had no idea we had been going so slowly.  We’ll step out a bit.”

He issued a command, and the speed of The Hawk increased.  But still, after an hour, they had failed to come up with the others.

“Well, it’s nothing to worry about I guess.  We know the way back as well as the others; besides, there is no particular hurry.”

Accordingly The Hawk continued at rather slow speed.

Half an hour later, Frank, forward, made out a dark hulk lying low in the water a short distance ahead.  He immediately called Lord Hastings’ attention to the object.

The latter acted quickly.

“Extinguish all lights quickly,” he called sharply.

The order was obeyed, and at a second command, The Hawk was slowed down so that she was barely moving.

“What’s the matter, sir?” exclaimed Jack, in great surprise.

“Matter is that there is a submarine dead ahead of us,” was his commander’s reply.

“You mean that dark object there?”

“Yes.”

“And are we going to sink her, sir?” asked Jack.

“We’ll have a try at it,” was the reply.  “In this darkness we can go very close without fear of being seen, The Hawk is so small.”

Fifty yards from the submarine, which lay quietly in the water, The Hawk came to a stop and the forward gun was made ready for action.