"I think I can pull the hay overboard now. It's a
small bale."

He stood up and jabbed his boat-hook into something. The next moment a
dark mass, in which red glowing embers could be seen, and which gave
out a dense smoke, splashed into the water with a loud hissing noise.

"There's still some fire in the boat!" cried Andy, as he saw tiny
tongues of flame.

"Yes, the woodwork is on fire, but a little water will douse that,"
cried Frank, as he caught up another pailful. With Bob using the
second pail, and Andy the pump, the fire was soon put out.

"Not so much damaged," observed Frank, as the three boys went aboard,
and examined the craft with a lantern. "But how in the world did it
start--or, rather, who put the hay here and set fire to it?"

"That's the question," admitted Bob. "All I know is that I was
standing talking to dad, when I smelled smoke, and saw it coming from
your boat."

"Did you see anyone around it to-night?" Andy wanted to know.

"Not a soul. We'll ask the pier master."

But when the boys, after making sure that no sparks of fire remained,
had gone back to the float, the dock master could give them no
information. He had not noticed any suspicious characters about, but
it was admitted that under cover of darkness, before the moon had
risen, someone might have rowed silently to the side of the _Gull_ and
started the fire smoldering in the bale of hay.

"But why would they want to do it?" asked Captain Trent.

"Give it up," said Frank. "Well, we might as well get back home, Andy.
Will you keep your eyes open for any more fires, Mr. Robinson?" he
asked of the caretaker of the yacht station.

"Sure I will, and they'll find they're in the wrong harbor if they try
any more tricks like that."

"Have you any suspicions?" asked Andy of his brother, as they were on
their way home.

"I sure have," was the answer.

"What are they?"

"Well, either the men who were disappointed in not getting the whale
did this, or it's up to that mysterious man who knows Paul Gale."

"I believe it's the latter. He wants to discourage us from trying to
get on his track."

"Probably. Well, we won't say anything about that part of it at home,
though we'll have to mention the fire. I hope we can make our trip
to-morrow to Seabright."

"So do I."

It was found the next morning that the _Gull_ was not much damaged,
and, though it smelled strongly of smoke, the two brothers did not mind
that as they