ing as to the possible
outcome.

"I'd give a month's pay to be aboard that destroyer," exclaimed Jerry
enviously. "That's the sort of excitement I like. Just imagine coming up
to that merchantman just in time to save her from destruction, and then
having a regular battle with the submarine, and finally watching her
sink, with a shell hole torn in her side!"

"Yes," added Slim, "and imagine being aboard that merchantman, with a
shell hole torn in her side before the destroyer arrives!"

"It's pretty cold swimming on a night like this," said Joe. "I've tried
it, and I know."

Lieutenant Mackinson, still seated before the wireless instrument,
signaled them for quiet again. Another message was coming through space.
It was in code, but was one that was easy for the lieutenant to
translate, for he had heard it before.

"Submarine disappeared. Returning to fleet. Convoying _Memphis_."

"Go on deck, keep your eyes busy off the port bow, and you may see
something interesting," the lieutenant told them.

Following the suggestion they went above and had stood there for perhaps
fifteen or twenty minutes when suddenly the lookout in the crow's nest
sang out: "Destroyer approaching, two points off the port bow."

Almost at the same instant there loomed out of the dense darkness a
faint light, apparently miles away. For a moment they would see it, and
then it would be gone, only to reappear again, another time to be
extinguished. But obviously all the time it was coming nearer.

They noted, too, that a similar process was being enacted by the cruiser
in the lead.

"What does it mean?" asked Slim.

"The destroyer is just using another sort of wireless," Joe explained.
"She is blinking her identity to the fleet, and the cruiser out there is
signaling recognition."

The next time the destroyer signaled she was almost abreast of them, but
about two miles away to the north. Her message then could be read by all
the boys. The words it spelled out, however, were a complete riddle:

"Love--sky--sand--curtain--run."

It was not for several hours that they learned that the captain of the
destroyer had flashed a message that he would convoy the _Memphis_
several miles further westward, and then rejoin the others, and that the
fleet commander, in flashing back "bundle," had given his O. K., with an
admonition for speed.

There being no further necessity for the spy watch which had been
maintained on the previous night