Suddenly the raft swayed gently; there was a parting of the water not a foot away toward the front, and then—­well, the ensuing events happened so quickly that their order is uncertain.

A black form arose from the water with a leap like lightning and landed squarely on the raft, which proceeded to perform its favorite dive.  It would have done so with much less persuasion, for the fish was a monster—­it appeared to me at that moment to be twenty feet long.

On the instant, as the raft capsized, Harry and I lunged with our spears, tumbling forward and landing on each other and on top of the fish.  I felt my spear sinking into the soft fish almost without resistance.

The raft slipped from under, and we found ourselves floundering in the water.

I have said the spear-thongs were fastened about our waists.  Otherwise, we would have let the fish go; but we could hardly allow him to take us along.  That is, we didn’t want to allow it; but we soon found that we had nothing to say in the matter.  Before we had time to set ourselves to stroke we were being towed as though we had been corks toward the opposite shore.

But it was soon over, handicapped as he was by four feet of spears in his body.  We felt the pull lessen and twisted ourselves about, and in another minute had caught the water with a steady dog-stroke and were holding our own.  Soon we made headway, but it was killing work.

“He weighs a thousand tons,” panted Harry, and I nodded.

Pulling and puffing side by side, we gradually neared the center of the lake, passed it, and approached the ledge.  We were well-nigh exhausted when we finally touched bottom and were able to stand erect.

Hauling the fish onto the ledge, we no longer wondered at his strength.  He could not have been an ounce under four hundred pounds, and was fully seven feet long.  One of the spears ran through the gills; the other was in his middle, just below the backbone.  We got them out with some difficulty and rolled him up high and dry.

We straightened to return for the spears which we had left at the edge of the water.

“He’s got a hide like an elephant,” said Harry.  “What can we skin him with?”

But I did not answer.

I was gazing straight ahead at the mouth of the passage where stood two Incas, spear in hand, returning my gaze stolidly.

Chapter XV.

The rescue.

I was quick to act, but the Incas were quicker still.  I turned to run for our spears, and was halted by a cry of warning from Harry, who had wheeled like a flash at my quick movement.  I turned barely in time to see the Incas draw back their powerful arms, then lunge forward, the spears shooting from their hands.

I leaped aside; something struck my leg; I stooped swiftly and grasped the spear-thong before there was time for the Inca to recover and jerk it out of my reach.  The other end was fastened about his waist; I had him, and giving an instant for a glance at Harry, saw that he had adopted the same tactics as myself.