CHAPTER XXVIII.

  A DESPERATE FIGHT.

  The colonel rose, and going down to the canoe helped himself to ahandful of crackers and some figs. He came back to his seat and began tomunch them very contentedly.

  "The most merciful thing we could do would be to cast our provisionsinto the lake," he said finally. "It would cut short the agony ofwaiting, but I don't suppose you would look at it in that way."

  "No, no; don't do that," cried Chutney. "Who knows what may happen yet?"

  "Ah! there you are again," said the colonel; "still clinging to hope oflife; still unable to realize the truth. You are only making it so muchthe harder for yourself."

  "But there is surely some outlet to this vast body of water?" saidMelton.

  "Yes," was the colonel's reply. "Undoubtedly, but it must be at thebottom of the lake; it certainly is not on the surface. Do you supposethose poor savages would have perished here if an outlet had existed?They, too, must have been carried by accident into the wrong channel,and no doubt they circumnavigated the lake, as we have done. Realizingthat they were lost, they either slew themselves to end theirsufferings or they fell victims to the serpents without muchresistance."

  While Melton and the colonel were carrying on this conversation, Guyrose and went down to the water, with the intention of gathering somefood, for he, too, was hungry.

  The canoe was pulled partly on shore, and as it leaked a little thewater had all collected in the stern, where Sir Arthur still lay inmerciful sleep, thus wetting the rugs.

  Guy noticed this, and with a view to making the sleeper morecomfortable, he slid the canoe down until it lay flat in the water. Itstill retained a slight hold of an inch or two on the sand.

  A sudden cry from the Greek brought him back in a hurry to the top ofthe island.

  His companions were staring out on the lake, and Canaris was pointingwith a trembling hand at some unseen object.

  "What is the matter?" cried Guy. "What do you see?"

  "Hush," said the colonel, holding up a warning finger. "Something ismoving out on the lake. Do you hear it splashing in the water?"

  As yet nothing could be seen, but the noise was very plain and distinct,a steady swish! swish! not unlike the beating of a little steamer.

  A chilling fear grew on them as they listened to this strange,mysterious sound.

  "Whatever it is, it is moving in a circle round the island," said Guy,"and keeping an equal distance from the shore."

  "You are right, Chutney," said the colonel, after a pause. "The soundwas on our left a moment ago. Now it is on our right."

  The Greek was correct. The surface of the lake was violently agitated,though not a breath of air was stirring, and a steady flow of rippleswas breaking on the sandy beach like tiny ocean waves.

  The unknown navigator, whatever it was, had nearly completed the circuitof the island now, and was very near the spot where they had first heardit.

  "It must be a serpent," cried Guy. "Heaven grant that it doesn'tapproach the island."

  He hurriedly picked up the torch and ran with it to the shore. Theradius of light thus thrown over the water illumined a space twentyyards ahead, and revealed a long, dark object moving in gracefulundulations over the surface. It was beyond doubt a huge serpent, and,as though angered by the light, the monster suddenly changed its course,and with a terrific splash headed directly for the shore. The huge headwas in plain view, and the eyes flashed back fire from the reflectedglare of the torch.

  For an instant all seemed paralyzed with horror, and no one moved.

  Chutney was the first to recover himself.

  "We must kill him before he reaches the island," he cried, staggeringback a pace or two. "Get the guns. Quick! quick! or it will be toolate!"

  He turned to flee across the island toward the canoe, but as he gainedthe ridge a cry of horror broke from his lips, and as his companionshurriedly reached the spot a single glance showed them what was thematter.

  The canoe was no longer on the shore. The swell caused by the approachof the serpent had washed it from its slight support, and now it wastwenty yards distant, and drifting farther and farther away with everysecond.

  "The guns! The guns!" shrieked Chutney. "They are all in the boat. Weare left at the mercy of the serpent. Sir Arthur! Sir Arthur!" heshouted with all his might, but no response came from the sleeping man,and the canoe continued to recede into the gloom.

  At this terrible moment it was Forbes who brought a ray of hope intotheir despair.

  Springing forward he snatched up an armful of the native weapons,spears, and axes, and distributed them to his companions.

  "We must fight the monster with these," he cried; "and while we arekeeping him off, you, Canaris, run to the shore and keep on shouting toSir Arthur. He may wake and get here in time to save us yet."

  "He must be in a faint," exclaimed the colonel, "or the noise wouldsurely have wakened him. Come on, Chutney, the serpent is halfway to theshore. We may keep him off with these arms."

  The torch was hastily placed in the sand near the water's edge, and,grasping their weapons firmly, they prepared to check the advance of themonster. Fortunately the spears and axes were of hard iron and fittedwith strong handles which the long storage in the cavern seemed to havetoughened.

  Meanwhile the air echoed with the Greek's loud cries, but at that momentnone thought of Sir Arthur or of the canoe, for the serpent was withinhalf a dozen yards of the island and his great body was undulatingthrough the water for thirty feet behind him.

  "Keep cool," said Chutney. "Aim well for the head and make every stroketell."

  The sight of the glaring eyes and the blood-red fangs was enough toappall the stoutest heart. They shrank back in uncontrollable fear, asthe long neck rose four feet in air and the body sank under the water.

  The monster uttered an angry hiss, but before he could spring Forbescast a spear with all his might and the sharp point pierced theserpent's body a foot below the head.

  "Back for your lives," he cried, and as they darted up the island themonster uttered a fearful sound, part hiss, part bellow, and flung halfhis length in contortions on the sand.

  Guy sprang forward and launched another spear that entered the slimybody near the center, but neither wound was mortal and the great serpentcame on unchecked.

  In one respect they had the advantage of him, as Guy accidentallydiscovered, for the wicked eyes blinked in the torchlight and themonster's actions showed that his powers of sight were limited todarkness.

  He was wonderfully quick and agile, however, for a sudden convulsiveleap carried him almost to the feet of his antagonists, and again theyscattered in alarm.

  The serpent's whole body was now on shore, with the exception of thetail, which was lashing the water to a milky foam.

  Seizing another spear Guy circled to one side, and boldly approachingthe trembling coils, with one terrific blow he planted his weapon intothe serpent's body so deeply that the spear pinned the monster firmly tothe ground.

  A cry of horror burst from his companions as the huge head swung roundwith awful quickness, but it missed Guy by barely an inch as he sprangaside.

  The serpent's contortions were now frightful to see, as he squirmed andtwisted to tear loose from the weapon. "Now let him have it," cried Guy;and in an instant the remaining spears, half a dozen in number, weredriven deeply into the venomous coils.

  The struggle was now at its crisis. With axes in hand they were dodgingabout the writhing monster, seeking a chance to reach the head, when anawful shriek echoed through the cavern, apparently from some distanceout on the lake, and then the Greek's voice was raised in a loud andurgent appeal for help. What new disaster threatened?