A glance into the boat sufficed to tell the naturalist that the figure in it was only a dummy.  He did not pause, but followed the trail up the hill, until he was close after the emissary ahead, going more slowly.

Only a few feet further along the cliff, the naturalist paused, too, keeping well under cover, for the man was now just ahead of him.  He looked fixedly at him and saw him gaze down the cliff.  Then he saw him slowly draw a gun.

Who could be below?  Quickly the naturalist’s mind seemed to work.  He crouched down, as if ready to spring.

The emissary slowly raised his revolver and took careful aim at the backs of Elaine and myself, as we came up the steps.

But before he could pull the trigger, the naturalist, more like one of the wild animals which he studied than like a human being, sprang from his concealment in the bushes and pounced on the man from behind, seizing him firmly.

Over and over they rolled, struggling almost to the brink of the precipice.

Elaine and I had got almost to the top of the flight of steps, when suddenly we heard a shout above us and sounds of a terrific struggle.  We turned, to see two men, neither of whom we knew, fighting.  One seemed to be a professor of natural history from his dress and general appearance.  The other had a sinister nondescript look.

Nearer and nearer the edge of the cliff they rolled.  We crouched closer to the rocky wall, gazing up at the death grapple of the two.  Who they were we did not know but that one was fighting for and the other against us we could readily see.

The more vicious of the two seemed to be forcing the naturalist slowly back, when, with a superhuman effort, the naturalist braced himself.  His foot was actually on a small ledge of rock directly at the edge of the cliff.

He swung around quickly and struck the other man.  The vicious looking man pitched headlong over the cliff.

We shrank back closer to the rock as the man hurtled through the air only a few feet from us.  Down below, we could hear him land with a sickening thud.

Far over the edge Elaine leaned in a sort of fascination at the awful sight.  For a moment, I thought the very imp of the perverse had got possession of her and that she herself would fall over.  She brushed her hand unsteadily over her eyes and staggered.  I caught her just in time.

It was only an instant before the brave girl recovered control of herself.  Then, together, we started again to climb up.

As we did so the naturalist looked down and caught sight of us approaching.  Hastily he hid in the bushes.  We reached the top of the stairway and gazed about for the victor in the contest.  To our surprise he was gone.

“Come,” I urged.  “We had better get away, quickly.”

As Elaine and I disappeared, the naturalist slowly emerged again from the bushes and looked after us.  Then he gave a hasty glance over the edge of the cliff at the man, twisted and motionless, far below.