Flying steel darts.
That arched tube of water looked to be about as broad as the belly of a ship. It was alive with twisting lightning, and blinked with flashes of red, blue, green, white and yellow. Watching it, Heineman worked out that those flashing things must be the zogo zalth. The flying needle darts were swirling round the arched tube of boiling water.
But not all of the zogo zalth had been drawn to that spectacular artefact. As Heineman and Grindle-Joyce hunkered on the beach, one of the darts came bounding along the pearlsands. Sprays of micropearls went zipping from the steel dart as it hit the sand repeatedly. Then it flashed past and was gone down the beach. [EoH Ch17]
Outside, in the night, one of the zogo zalth came drifting through the darkness. The dart of living steel slowed as it neared the windows, perhaps sensing its own reflection. It came to a dead halt just beyond the glass, then hung there, buoyed up by its aura of golden light. The night was so quiet that Heineman could hear its humming, barely muted by the intervening glass.
Abruptly, the needle-dart jolted forward, stabbing at the window. There was a sharp !crack! as the glass fractured. Then the hum of the dart rose to a scream as it veered away and went shooting through the night, gaining speed as it accelerated toward the horizon. When he was quite sure it was gone, Heineman examined the window, and found a crack which ran from top to bottom, the whole window now just a finger's jolt from collapse. [EoH Ch11]