"That's--right!" gasped Andy.

The brothers were now at the gangway leading down to the float.

Several men and boys who had been fishing off the end of the pier were gathered there, and it was they who had been shouting.

"Guess your boat's a goner," observed Captain Trent. "Bob has gone out to her."

There was now more smoke than fire aboard the _Gull_, but it seemed to the boys only a matter of a few seconds when the flames would again break out.

"Is there a pump? Has anyone a pump?" begged Frank.

"Here's a small one they use to get the bilge water out of their motor boats," said the dock master, for the pier was a station for a yacht club, and the dock-keeper lived in a small house on the pier. "It doesn't throw much of a stream, though."

"Better use pails," cried Captain Trent. "Here are a couple I use for clams. Take 'em along. The fire started sudden-like, when we were all standing here talking about the whale."

Andy and Frank did not stay to hear more. Quickly they shoved off in their skiff and were soon approaching the _Gull_, at the side of which Bob Trent now was.

"It's a lot of hay smoldering!" he shouted. "Maybe I can get it overboard with my boathook. Come on, fellows."

"Row! Row!" cried Frank, for Andy had the only available pair of oars.

"I am rowing as hard as I can. Hay on fire! We had no hay on our boat. Someone must have put it there and tried to burn it!"

"I guess so. But don't talk--save your breath for rowing."

A minute later Frank and Andy were beside Bob in his boat. Dense smoke was pouring from the _Gull_, and Frank, dipping up a pailful of water, dashed it into the c.o.c.kpit. There was a hiss, showing that fire was present.

"Wait!" cried Bob. "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 ma.s.s, 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 prepared for the cruise to Seabright.

"Think we'll get any clue?" asked Andy, as he cast off, while Frank ran up the sail.

"Well, it won't be from want of trying. We'll keep a good lookout on the way up, and then we'll go ash.o.r.e there and make some inquiries.

I'm going to get at the bottom of this mystery if it's at all possible," and Frank looked very determined as he fastened the throat and peak halyards on the cleats and looked to see if the sheet was running free in the blocks.

On the trip up the coast the boys kept a sharp watch for anything resembling a wrecked motor boat, or for one in good condition resembling the towing craft of which Jack Kett had spoken. They saw nothing, however, even though they sailed out to sea several miles.

"Let's head for Seabright now," proposed Andy, as they swung about on a long tack. "Maybe he's there waiting for us."

"He'll run if he sees us," jokingly replied Frank.

In about an hour the boys had made their craft fast to the Seabright pier, and going to the office of the dock master they inquired for a motor boat that answered the description of the one for which they were looking.

"We have so many craft here in the summertime," said the dock official, "that it's a pretty hard matter to remember 'em all. I don't recall the boat you speak of, and I'm sure no motor craft that was partly burned has put in here. But speaking of a tall dark man, I recollect now that Jim Hedson, who runs the sailboat _Mary Ann_, was telling me he had a fellow come to him and want to hire her. Maybe that's the fellow you're looking for."

"Perhaps!" agreed Andy eagerly. "Where is Jim Hedson?"

"Over there," and the dock master pointed to where a group of sailors and fishermen were seated on an overturned boat on the beach.

"We'll talk to him," proposed the elder Racer lad, and, followed by his brother, he approached the little gathering. Before they reached the men Andy uttered a sudden exclamation.

"Look!" he cried to his brother, pointing up the street which led down to the water front. "That man--the mysterious stranger--here he comes!"

"Sure enough!" agreed Frank, as he saw a tall dark man hurrying toward the pier. "That's him all right."

The boys stood waiting, hoping against hope that they could now solve the mystery. The man hastened forward. All at once he caught sight of the lads.

Like a flash he wheeled about and fairly ran back up the street, while Frank took after him calling:

"Hey! Hey! Wait a minute! Stop!"