ng that side from direct assault.
Groups of Scaly Ones took shelter behind tree trunks and mounds of earth
and any other possible cover, firing their gas-guns up at the
battlements in an effort to lessen the arrow fire. Others crept forward
behind movable metal shields. Heavy-caliber gas-guns inched slowly
forward behind wooden mantlets that bristled with arrows, and hurled
their larger explosive bullets up at the walls. Wherever they struck
there was a puff of yellow dust and a scarred place on the stones.
Reptilian trumpets beat with a staccato thunder as Lansa kept in touch
with his various divisions. Not all the advantage was with the
besiegers, however. Even as Gerry watched, a blue heat-ray struck full
on one of the big gas-guns and blew it up with a shattering crash.

In all but one particular the battle was a large-scale edition of the
type of assault that the Scaly Ones had often tried against various
barrier forts in the past. The difference was that they now possessed
the supode ray, which Lansa had been able to prepare for his forces.
Long beams of the familiar murky, reddish light were continually
playing upon the walls of Larr.

The effect of the supode rays seemed to be less serious than Gerry would
have expected. Perhaps Lansa's ray-guns were lacking in power because
inefficiently made. Perhaps the yellow stones that formed the walls of
Larr contained some radioactive substance that partially neutralized the
rays. The walls were crumbling into powder in dozens of small spots as
the searching beams of the rays found a weak point or flaw in the stone,
but there was none of the wholesale collapse that Lansa had probably
hoped to achieve.

The whole scene below was like a macabre nightmare. The fires flashed
and crackled, and the explosive bullets of the Scaly Ones twinkled like
fire-flies through the drifting smoke. Red light glinted on the points
of flying arrows. Savissan trumpets blared defiance to the thunder of
reptilian drums. Most dramatic of all, silent but terribly deadly, was
the duel of the ray-casters as the red beams of the attackers and the
blue rays of the defenders darted back and forth through the night like
the rapiers of fencing giants.

* * * * *

The flotilla of flying cars darted down to the plaza in front of the
Tower of the Arrow. The pilots kept them invisible until they had
landed, lest the nervous crew of a defending ray-machine blast them
befo