With a cautious movement of the knife he slit the fish along the back.
There was a strange hissing and the ray of fire swung loose the end of its tail.
It caught Dave around the wrist, holding that member as in a vise.
At first the youth was inclined to drop the knife, but he managed to hold on.
Then began an intensely interesting struggle between boy and fish.
Dave tried his best to twist the hand around so that he might cut the fish a second time.
He brought up his other hand, in an endeavor to transfer the knife, but as quick as a flash the ray of fire unloosened itself and caught both wrists.
In its own way it was fighting for its mate, a prisoner in the net.
Dave's two hands were now drawn tightly to his father's throat, as if the horrible monster of the deep meant to make the boy strangle his own parent!
"I must get my hand free!" thought the young diver.