prayed force-shells along the building's side.

* * * * *

The shells struck and whiffed away the whole side, exposing the level
on the building's interior. Out from it rushed swarms of crazed green
men, sweeping aside the frog-men guards, while far over the city the
invading craft were loosing shells on the block-like buildings that
held the prisoners, tens of thousands of them swarming forth. In the
throng below as they raced madly forth Norman saw one, and shouted
wildly. The one brown garbed figure looked up, saw their boat swooping
lower, and leaped for it in a tremendous forty-foot spring that
brought his fingers to its edge. Norman pulled him frenziedly up.

"Norman!" he babbled. "In God's name--Fellows--!"

"That helmet, Hackett!" Fellows flung at him. "My God, look at those
prisoners--Norman!"

The countless thousands of green men released from the buildings whose
walls had vanished under the shells of the invaders had poured forth
to make the amphibian city a chaos of madness. Oblivious to all else
they were throwing themselves upon the city's crowding frog-men in a
battle whose ferocity was beyond belief, disregarding all else in this
supreme chance to wreak vengeance on the monstrous beings who had fed
upon their blood. In the incredible insanity of that raging fury the
craft of the green men hanging over the city were all but forgotten.

Suddenly the city and the mighty dome over it quivered violently, and
then again. There came from beneath a dull, vast, grinding roar.

"The great force-bombs!" Fellows screamed. "They've set them off--the
city's sinking--out of here, for the love of God!"

The boat whirled beneath Sarja's hands toward the pool of the
water-tunnel, all their fleet rushing with them. The grinding roar was
louder, terrible; dome and city were shaking violently now; but in the
insensate fury of their struggle the frog-men and their released
prisoners were hardly aware of it. The whole great dome seemed sinking
upon them and the city falling beneath it as Sarja's craft ripped down
into the tunnel's waters, and then out, at awful speed, as the great
tunnel's walls swayed and sank around them! They shot out into the
green depths from it to hear a dull, colossal crashing through the
waters from behind as the great pedestal of rock on which the city had
stood, shattered by the huge force-bombs, collapsed. And as their
boats flashed up into the open air they sa