"Look!" The radiance was marching--_marching_--down the colossal bridge.

It moved swiftly, in some unthinkable way _intelligently_.

It swathed the _Akka_, and closer, ever closer it swept toward the approach upon which Yolara's men had now gained foothold.
From their ranks came flash after flash of the green ray--aimed at the abode! But as the light sped and struck the opalescence it was blotted out! The shimmering mists seemed to enfold, to dissipate it.
Lakla drew a deep breath.
"The Silent Ones forgive me for doubting them," she whispered; and again hope blossomed on her face even as it did on Larry's.
The frog-men were gaining.

Clothed in the armour of that mist, they pressed back from the bridge-head the invaders.

There was another prodigious movement at the ends of the crescent, and racing up, pressing against the dwarfs, came other legions of Nak's warriors.