of their native land. To this end, three of
them---Hugh Hardin, his chum Billy Worth, and Chester Brownell---had
gladly accepted an invitation from the fourth, Alec Sands, to
spend a month at Palmdune, the Florida residence of Alec's father,
who had sent them on this cruise. With them Mr. Sands had sent
his secretary, a young man named Roy Norton, who had left them
temporarily at Key West while he attended to business in Havana.
When he had returned from Havana, he had found a new member of
the party---Mark Anderson, the son of the captain of Red Key
Life-Saving Station.

The _Arrow_ had been anchored off Snipe Point during the previous
night, where Captain Vinton had gained the information which made
him decide to return to Key West. This knowledge, which he had
already imparted to the boys, was to the effect that throughout
the night before, while he and Dave alternately watched, he had
seen a gray steamer or perhaps a gunboat cruising among the islands
off the Point, occasionally coming close enough to the beach to
be made out distinctly, but showing no lights and making no signals.

Immediately his suspicions had been aroused by this mysterious
action. His impression was that the vessel belonged to a country
which was then hostile to the United States. In that case she
was either grappling for the cable between Key West and the mainland
terminus at Punta Rossa, which lay close inshore at Snipe Point,
or was trying to make connection with some other vessel carrying
supplies or ammunition from some West Indian port, perhaps intending
to run the blockade.

Why she should attempt to tamper with the cable, he could not
understand, knowing the superior efficiency of the wireless system;
but he thought she might be one of the elusive filibustering vessels
reported to have been seen in the Gulf of Mexico several days before
this.

Stories about these mysterious vessels had caused official orders
to be sent to Tampa and to Galveston, Texas, concerning the departure
of several transports with American troops. And Captain Vinton
himself had almost encountered a notorious filibuster named Juan
Bego, one night during the earlier part of this pleasure cruise;
that is, he had sighted a vessel which he felt sure was the _Esperanza_
of Captain Bego, in waters which were supposed to be debarred to the
enemy. All this had tended to make him more alert and wary than
ever, even suspicious; and he had resolved to lose no ti