uddenly. "This is getting pretty
monotonous."

As he spoke the boy paid nut a little more line. He had only just time
to belay it round the cleat to avoid its being jerked out of his hand,
so fast was the creature they had hooked now traveling.

"Say, Tubby," spoke Merritt at length, "I'm beginning to think myself
that it might not be a bad idea to put back. Those clouds over there
on the horizon look as if they meant trouble."

"Oh, let's keep it on a little while longer pleaded Tubby; cutting
through the water like this, without any expenditure of gasoline or
power, is the real luxurious way of ocean traveling. It beats the
Mauretania. Just think if liners could hitch a whole team of things
like whatever has got hold of us to their bows! Why, the Atlantic would
be crossed in four days."

For some time longer the boat shot along over the waves, towed by its
invisible force. The boys, with the exception of Tubby, began to get
anxious. The shores of the mainland were dim in the distance behind
them, and Topsail Island itself only showed as a dark blue dot.

Suddenly the motion ceased.

"He's free of the line!" shouted Hiram, inwardly much relieved to think
they had got rid of what to him was an alarming situation.

"No, he's not," replied Tubby, bending over the line. "He's still fast
to us. The line's as tight as a fiddle string."

He was standing up as he spoke, and as the Flying Fish gave a sudden,
crazy jerk forward, he was almost thrown overboard. In fact, he would
have toppled into the sea if Merritt had not bounded forward and
grabbed the fleshy lad just as he was losing his balance.

"We're off again!" exclaimed Hiram, as the Flying Fish once more began
to move through the water.

But now the creature that had seized Tubby's big hook started to move
in circles. Round and round the Flying Fish was towed in dizzy swings
that made the heads of her young occupants swim.

"Start the engine on the reverse, and see if that will do any good,"
said Tubby, bending anxiously over his line.

Merritt brought the reverse gear to "neutral," and then started it up,
gradually bringing back the lever governing the reversing wheel till
the Flying Fish was going second speed astern, and finally at her full
gait backward.

The tug thus exercised seemed to have no effect on the monster that had
caught Tubby's bait, however. With the exception that the speed was
diminished a trifle, the Flying Fish was still p