"Then go it is!" decided Percy.

He headed the pea-pod for the Dog and Pups.

"We'll keep a sharp lookout, and if it starts to grow anyways thick
we'll strike back for old Tarpaulin."

A pull of about twenty minutes brought them to the ledges, around which
the traps were set in a circle. They began hauling at the point in the
circumference nearest to the island, following the buoys west and north.
The catch exceeded their hopes.

"We'll need another tub, if this keeps up," chuckled Percy.

Filippo laughed jubilantly. The fog was forgotten. Their entire
attention was centered on the contents of each trap as it was pulled.

Round on the edge of the circle farthest from the island a pot refused
to leave bottom. Percy tugged till he was red in the face, but he could
not start it.

"Catch hold with me, Filippo!" he puffed.

The Italian joined his strength to Percy's, but to no avail. The slacker
still clung to the bottom. The boys straightened up, panting.

"We'll have to leave it," acknowledged Percy, disappointedly. "Probably
there's half a dozen two-pound lobsters in it."

He looked about and gave a startled cry.

"Where's the island?"

The wooded bluffs of Tarpaulin had disappeared. While they had been
wrestling with the stubborn trap the fog had stolen a march on them. On
all sides loomed a horizon of gray mist, not a half-mile distant and
steadily drawing nearer. They must locate the island and get back to it
at once.

Percy tossed over the buoy and the warp at which they had been pulling.
Tarpaulin lay southwest; but which way was southwest? Busied with the
trap, he had utterly lost all sense of direction. The sun? He glanced
hopefully up. No; that would not help any. The fog was too dense. Ha!
The surf?

"Listen hard, Filippo!" he exhorted.

They strained their ears. No sound. The swell was so gentle that it did
not break on the ledges of the island loudly enough to be heard a mile
and a quarter off. The heaving circle of which they were the center was
contracting fast. Its misty walls were now less than five hundred feet
away.

"Guess we'd better take a buoy aboard, and hang to it till Jim comes out
to hunt us up. It'd make me feel cheap to do it, but it's the only safe
way. But wait! What's that?"

Both listened again. A sound reached their ears, plain and unmistakable,
the rote of dashing water.

"There's the surf!" rejoiced Percy. "Don't you hear it?"

"_Si_, I hear it," answered Filippo