As he pressed trigger, a light sighing eased itself from the slim barrel.  Something flicked through the leaves; and, almost on the instant, the phenomenon of the little phosphorescent spot repeated itself, though in a different place from the first one.  Captain Alden’s and Rrisa’s shots produced still other blurs of virescence.

Then, as they all waited, crouching, came another and another tiny explosion, high aloft, at precisely ten-second intervals.  Here, there, they developed, until twenty-nine of these strange, bubble-like things had burst above and all about the huge enclosure.  Then darkness and silence once more settled down.

Nothing seemed to have happened.  Night still reigned, starry with glimpses of sky through wind-swayed trees.  One would have said everything still remained precisely as it had been before.

Yet presently, within the stockade or near it, a certain uneasy melange of sounds began to develop.  Here a cry became audible, there a command.  A startled voice called an order, but suddenly fell silent, half-way through it.  The worrying of the dog ceased with eloquent suddenness.  A curse died, unfinished.

And silence, as perfect as the silence of the unseen watchers strung all about the periphery of the stockade, once more dominated the night.

For precisely ten minutes, nothing broke that silence—­minutes during all of which the Master remained calmly waiting, with grave confidence.  Bohannan shuddered a little.  His Celtic imagination was at work, again.  Uncanny the attack seemed to him, unreal and ghostlike.  So, perhaps, might strange, unbelievable creatures from some other planet attack and conquer the world, noiselessly, gently, irrevocably.

This assault was different from any other ever made since man and man first began battling together in the dim twilights of the primeval.  Not with shout and cheer did it rush forward, nor yet with venomous gases that gave the alarm, that choked, that strangled, that tortured.

Silence and concealment, and the invisible blight of sleep, like the greater numbing that once fell on the hosts of Sennacherib, enfolded all opposition.  All who would have stood against the Legion, simply sighed once, perhaps spoke a few disjointed words, then sank into oblivion.

So far as anyone could see, save for the bursting of twenty-nine insignificant little light-bubbles, in mid-air, nothing at all had happened.  And yet tremendously much had happened, inside the huge stockade.

Ten minutes to a dot had drifted by, seeming at least six times as long, when all at once the Master stood up.

“The gas has dissipated enough now,” said he, “so that we can advance in safety.  Come!”

The three also arose, half at his command, half from the independent impulses given them by their watches as these came to the designated second for the forward movement.  The Master blew no whistle, gave no signal to the many others scattered all through those darkly silent woods; but right and left, and over beyond the stockade, he knew with the precision of a mathematical equation every man was at that exact moment also arising, also obeying orders, also preparing to close in on the precious thing whereof they meant to make themselves the owners.