g monster, seeking a chance to reach the head, when an
awful shriek echoed through the cavern, apparently from some distance
out on the lake, and then the Greek's voice was raised in a loud and
urgent appeal for help. What new disaster threatened?

CHAPTER XXIX.

GUY SAVES SIR ARTHUR.

This new alarm, coming just at the uncertain period of their struggle,
was quite enough to strike despair to the hearts of all.

"That was Sir Arthur's voice we heard first," exclaimed Forbes. "And it
is Canaris who is shouting for help. What are we going to do about it?"

"Tell him to hold out for a moment," cried Guy. "I'll wind up this
affair pretty quick."

Raising the axe, he made a sudden dart forward and buried the blade deep
in the serpent's head. It was a clever stroke and so forcible that the
axe was jerked from his hand.

The colonel dragged him hastily back, but the danger was over. The
monster was thrashing the blood-stained sand in his death agonies,
powerless to do further harm.

Canaris was still calling for help, and, leaving their dying antagonist,
the others plunged across the island. The Greek was running up and down
the strip of sand, and far out on the lake the canoe was visible in the
radius of light, with Sir Arthur standing erect in the bow.

"He won't take the paddle!" exclaimed Canaris. "He says there is
something splashing in the lake beyond him. He's a dead man if he
doesn't get back to the island."

"Sir Arthur," shouted the colonel, "come back; paddle for your life. Do
you hear me?"

The only response was a cry of fright. Sir Arthur was plainly too dazed
to be capable of action. He had just wakened, and the horror of his
situation was too much for him.

"Save me! Save me!" he cried. "The serpent is coming; I can hear it
splashing the water."

"Take the paddle," shouted Guy, "and steer for the island. If you don't
you are lost."

This seemed to arouse the imperiled man to action. He snatched up a
paddle and, dropping to his knees, drove the canoe forward with frantic
strokes.

His companions encouraged him with cheering words as he came nearer. The
island was barely twenty yards distant when the paddle slipped from his
grasp. He turned round, apparently to pick up another, and then threw
himself with a dismal cry to the bottom of the canoe.

The cause of his new and sudden fright was readily seen. On the edge of
the gloom, not many yards beyond the canoe, a violent agitation of th