Only for an instant, though.  She has seen and recognized Lawrence Hayne.  Concealed from them he is following Mr. Van Antwerp, and there can be but one purpose in his coming here,—­Nellie.  But what can he want with her—­her rightful lover?  She springs from the lower step on which she has been standing, runs across the tessellated floor, and stops short in the door-way, gazing after the two figures.  She is startled to find them close at hand,—­one, Van Antwerp, close to the railing, facing towards her, his features ghastly in the moonlight, his left hand resting, and supporting him, on one of the tall wooden pillars; the other, Hayne, with white clinching fists, advancing upon him.  Above the low boom and roar of the surf she distinctly hears the clear tenor ring of his voice in the tone of command she last heard under the shadow of the Rockies, two thousand miles away: 

“Halt!”

No wonder a gentleman in civil life looks amazed at so peremptory a summons from a total stranger.  In his high indignation will he not strike the impertinent subaltern to earth?  As a well-bred woman, it occurs to her that she ought to rush out and avert hostilities by introducing them, or something; but she has no time to act.  The next words simply take her breath away: 

“Sergeant Gower, I arrest you as a deserter and thief!  You deserted from F troop, ——­th Cavalry, at Battle Butte!”

She sees the fearful gleam on the dark man’s face; there is a sudden spring, a clinch, a straining to and fro of two forms,—­one tall, black, snaky, the other light, lithe, agile, and trained; muttered curse, panting breath, and then, sure as fate, the taller man is being borne backward against the rail.  She sees the dark arm suddenly relax its grasp of the gray form and disappear an instant.  Then, there it comes again, and with it a gleam of steel.  With one shriek of warning and terror she springs towards them,—­just in time.  Hayne glances up, catches the lifted wrist, hurls his whole weight upon the tottering figure, and over goes the Knickerbocker prone upon the floor.  Hayne turns one instant:  “Go in-doors, Mrs. Rayner.  This is no place for you.  Leave him to me.”

And in that instant, before either can prevent, Steven Van Antwerp, alias Gower, springs to his feet, leaps over the balcony rail, and disappears in the depths below.  It is a descent of not more than ten feet to the sands beyond the dark passage that underlies the piazza, but he has gone down into the passage itself.  When Mr. Hayne, running down the steps, gains his way to the space beneath the piazza, no trace of the fugitive can he find.

* * * * *