“Narrow squeak that, Walsh!  That devil has crawled close up on us.  Can you see him?”

“Begad, sir, I can see nothing at all but rocks, rocks, rocks.  How can a man fight anyway agin’ human beings that crawl like snakes?”

Zip!  Another shot close at hand, too, and from another unseen foe.  The first came from somewhere among the bowlders down to the southeast, and this second whizzed from across the canon.  A little puff of blue smoke is floating up from among the rocks fifty yards or so to the north of the narrow slit.

Crouching lower, Drummond calls across to Costigan, posted as the easternmost of the two men on the opposite side,—­

“That fellow is nearest you, corporal; can you see nothing of him?”

“Nothing, sir; I was looking that way, too, when he fired.  Not even the muzzle of his gun showed.”

This is serious business.  If one Indian or two can find it so easy to creep around them and, armed only with their old muzzle-loading guns, send frequent shots that reach the besieged “in reverse,” what can be hoped when the whole band gathers and every rock on every side shelters a hostile Apache?  From the first Drummond has feared that however effective might be these defences against the open attack of white men, they are ill adapted to protect the defenders against the fire of Indians who can climb like squirrels or crawl or squirm through any chink or crevice like so many snakes.

Another shot!  Another bullet flattens itself on the rock close to his right shoulder and then drops into the dust by his knee.  It comes from farther up the cliff,—­perhaps two hundred yards away among those stunted cedars,—­but shudderingly close.  Costigan and the other men glance anxiously over their shoulders at the point where their young commander and Walsh are crouching.  They are not yet subjected to a fire from the rear, these others.  The lookout, the signal-station, as it might be called, is the highest point and most exposed about the position.

“For God’s sake, lieutenant,” cries the corporal, “don’t stay there.  They’ve got your range on two sides anyhow.  Come out of it.  You and Walsh can slip down as we open fire.  We’ll just let drive in every direction until you are safe below.”

Drummond hesitates.  He sees a half-pleading look in Walsh’s honest face.  The Irishman would willingly tackle the whole tribe in open fight, but what he doesn’t like is the idea of being potted like a caged tiger, never knowing whence came the shot that laid him low.  Then the lieutenant peers about him.  Yes, it is exposed to fire from a point in the cliffs to the west, and there are rocks over there to the north that seem to command it; but if abandoned there will be no way of preventing a bold advance on part of the Apaches up the rugged eastward slope.  It would then stand between the defenders and the assailants, giving to the latter incalculable advantage.  Hold it he must for a few minutes at least, until, recalling McGuffey, he can set him and one or two others to work piling up a rock barricade in front of the cave.  Then if driven out and no longer able to stand the Indians off, they can retire into the caves themselves, hide their precious charges in the farthest depths, and then, like Buford at Gettysburg, “fight like the devil” till rescue come.