The silence drew at them like a pain.  Rrisa breathed something in which the words:  “La Illaha ilia Allah” transpired in a wraith of sound.  Alden nestled closer into the ferns.  Bohannan could hardly hold his poise.

All three now had their capsule pistols ready.  The self-luminous compass and level attached to each gun gave them their exact direction and elevation.  Glimmering watches marked the time, the dragging of the last few seconds.

The Master drew no weapon.  His mind, directing all, observing all, was not to be distracted by even so small a detail as any personal hand in the discharge of the lethal gas.

If he felt the strain of the final moment, on which hung vaster issues than mere life or death, he gave no indication of it.  His eyes remained fixed on the watch-dial at his wrist.  They were confident, those eyes.  The vague shimmer of the watch-glow showed them dark and grave; his face, faintly revealed, was impassive, emotionless.

It seemed the face of a scientist, a chemist who—­having worked out his formula to its ultimate minutiae—­now felt utter trust in its reactions, now was only waiting to observe what he well knew must inevitably happen.

“Thirty seconds more,” he whispered, and fell silent.  Presently, after what seemed half an hour:  “Fifteen!”

Another long wait.  The Master breathed: 

“In just five seconds the first capsule will burst there!” He pointed with assurance.  “In two—­in one—­”

CHAPTER VI

THE SILENT ATTACK

At the exact instant when the second hand notched to the minute’s edge, and in precisely the spot indicated, a slight, luminous spot became dimly visible above the trees.  The spot took uncertain form high above the ghost-glow rising from the unseen stockade.  For an instant it hung suspended, pale-greenish, evanescent.

Then, as a faint plop! drifted to the watchers—­a sound no louder than a feeble clack of the tongue—­this indefinite luminosity began to sink, to fade, falling slowly, gradually dissipating itself in the dim light over the stockade.

The Master nodded, smiling, with never any hint of praise or approbation.  The fulfilment of his order was to him no other than it is to you, when you drop a pebble into water, to hear the splash of it.  That his plan should be working out, seemed to him a perfectly obvious, inevitable thing.  The only factor that could possibly have astonished him, just now, would have been the nonappearance of that slight, luminous cloudlet at the precise spot and moment designated.

Neither Bohannan, Alden, nor Rrisa was watching the slow descent of the lethal gas.  All three had their eyes fixed on their own lethal-gas pistols and on their watches.  At mathematically the correct second, Bohannan discharged his piece, correctly sighting direction and elevation.