the
_Gull_, sailing her back to Harbor View.

"Before you go I wish you'd call at Captain Trent's fish store, and get
me some lobsters," requested Mrs. Racer. "I want some for dinner
to-night."

"And Andy wants one for a leg bracelet," added Frank with a laugh.

"Aw, cut it out!" begged his brother.

They stopped in the fish store on their way to the depot. There they
found Bob, busily engaged in putting up clams, and other products of
the sea, for customers. Andy remarked to the captain that he thought
he had a new clue to the mysterious man.

"And that reminds me, that I meant to ask you where he would likely be
heading for when he drove us back," put in frank.

"Where was he?" inquired the old seaman, and the brothers described the
location.

"By Neptune!" suddenly exclaimed the captain. "I shouldn't wonder but
what he was going to Cliff Island!"

"Cliff Island!" cried Frank.

"Yes, you know that group of rocks--it's not much more than ten miles
from the Shark Teeth."

"Sure we know where it is," agreed Andy "But no one lives on it. It's
as desolate as a volcano."

"All the better for what that man wanted," declared die captain. "Take
my word for it he's gone there with the damaged motor boat, though why
I can't say. But he wants to be let alone, and that's the best place
he could pick out for the purpose. Why don't you go there?"

"I believe we will!" cried Frank. "We didn't know just how to begin
the search, but that's the best clue yet."

"On to Cliff Island!" cried Andy.

"Hush! Not so loud," cautioned his brother. "You can't tell who might
hear you."

Then, having ordered the lobsters, they hurried away to take the train
for Mardene to get the sailboat. Once more they were on the search for
the mysterious man.

CHAPTER XVII

ON CLIFF ISLAND

"Why didn't we think before of going to the island?" asked Andy, as he
and his brother sat in the train on the way to Mardene.

"Give it up," answered Frank. "But, as the captain says, it would be
just the place for a criminal to hide. Hardly any boats stop there if
they can help it, unless they want shelter from a storm, and it's out
of the line of regular travel. Still, we may not find our man there."

"Yes, but it's a good chance. There's a fine wind to-day, and we
oughtn't to be a great while running to the island."

The brothers discussed the curious case into which they had been drawn
since rescuing Paul Gale, and they