We had swept over toward the right wall of the cleft and were gliding over a broad ledge. This ledge was, I judged, all of a hundred feet in width. From it the floor of the place was dropping rapidly.
The opposite precipices were slowly drawing closer. After us flowed the flanking host.
Steadily our ledge arose and the floor of the canyon dropped. Now we were twenty feet above it, now thirty. And the character of the cliffs was changing. Veins of quartz shone under the metallic plating like cut crystal, like cloudy opals; here was a splash of vermilion, there a patch of amber; bands of pallid ochre stained it.
My gaze was caught by a line of inky blackness in the exact center of the falling floor. So black was it that at first glance I took it for a vein of jetty lignite.
It widened. It was a crack, a fissure. Now it was a yard in width, now three, and blackness seemed to well up from within it, blackness that was the very essence of the depths. Steadily the ebon rift expanded; spread suddenly wide open in two sharp-edged, flying wedges—
Earth had dropped away. At our side a gulf had opened, an abyss, striking down depth upon depth; profound; immeasurable.
We were human atoms, riding upon a steed of sorcery and racing along a split rampart of infinite space.
I looked behind—scores of the cubes were darting from the metal host trailing us; in a long column of twos they flashed by, raced ahead. Far in front of us a gloom began to grow; deepened until we were rushing into blackest night.
Through the murk stabbed a long lance of pale blue phosphorescence. It unrolled like a ribbon of wan flame, flicked like a serpent's tongue—held steady. I felt the Thing beneath us leap forward; its velocity grew prodigious; the wind beat upon us with hurricane force.
I shielded my eyes with my hands and peered through the chinks of my fingers. Ranged directly in our path was a barricade of the cubes and upon them we were racing like a flying battering-ram. Involuntarily I closed my eyes against the annihilating impact that seemed inevitable.