bodyguard were now out of sight of land. The sun
shone brightly and the day was perfectly calm. There was scarcely a
ripple upon the smooth surface of the sea.

Below, aboard the _Glasgow_, the passengers were at dinner. They were
laughing and joking among themselves.

Aboard the motorboats all was peacefully quiet. The men not on duty were
idling about and talking.

Suddenly Edwards, who stood forward on _The Hawk_, caught the peculiar
fluttering of the signal flags aboard the _Glasgow_.

"_Glasgow_ signalling, sir," he reported to Lord Hastings.

Lord Hastings quickly drew the attention of Commander Thompson to the
_Glasgow's_ signals, at the same time deciphering them for Frank and
Jack.

The first signal read:

"Small vessel dead ahead."

Commander Thompson flashed back his response:

"Submarine?"

"Can't make out yet," was the answer.

There was some further wig-wagging; and then the need for this means of
communication suddenly ceased.

There came a sharp blast from the _Glasgow's_ horn and the big ship
slowed down abruptly. Then came the sound of a shot from dead ahead and
there was a splash between the _Glasgow_ and _The Hawk_.

"The enemy!" exclaimed Lord Hastings.

Aboard each of the small motorboats every man sprang to his post. Soft
commands carried back and forth across the water, while the signal flags
of the Glasgow continued to flutter.

Then, even as Lord Hastings received from the _Lion_ the command to
advance, he read the last signal of the _Glasgow_.

"Submarine has halted us," it read. "Dead ahead."

The motorboat fleet came to life upon the instant. Again it divided into
two parts, one passing on each side of the _Glasgow_, and darted forward
toward the enemy.

Aboard each the forward guns were manned, the gunners ready to fire at
the word.

On the _Glasgow_ all was confusion. Passengers, attracted by the sound
of the shot from the submarine, sprang from their tables and dashed on
deck. There, as they made out the submarine, they turned pale. Only the
reassuring voices of the officers averted a panic.

Then the passengers turned their attention to the fleet that was now
passing around the big liner to the attack.

Rapidly the little craft sped forward and before the submarine commander
had divined their presence, they were swooping down upon him, seemingly
from all directions. Stunned at this unexpected arrival and before he
could give a word of command, _The Hawk_ unlo