e doodad on it!"

The Chief responded audibly. "You didn't forget to go first into that
doorway to hell," he said drily. "You fool Irishman, go back down and
try the thing; give the 'little doodad' a chance!"

* * * * *

Once more the red ship fell swiftly under Danny's hand. As before, the
valley yawned like the living threat of a volcano in eruption. But
this time, instead of the whining nitro-producers, there came from
beneath the ship a discordant shriek like nothing that the quiet
mountains had ever heard. And Danny's fingers played over a strange
keyboard whose three keys were rheostats, and the crashing discord
below rose to a horror of sound that tore and battered at the ship's
thick walls to set the nerves of the crouching man a-jangle. But his
eyes, watching through a lookout below, saw strange disturbances of
the flames; he saw the masses of flame shiver as if stricken--fall
apart--vanish!

And he held the sound controls at that same horrendous shriek while
his ship swept on and the thunder of her passing was lost in the
pandemonium that went before. But the valley, when the red ship had
passed, was a place of charred skeleton trees--of gray, swirling
ashes, and of embers, here and there, that blew back to life only to
be smothered by the gases of the ships that followed in his wake.

And the voice that spoke from the instrument beside him still spoke
drily. "There's fifty miles more of that ahead," said the voice. "Just
keep moving along; we'll mop up behind you.... Oh, and by the way,
O'Rourke, give my congratulations to the Infant on the success of his
invention. His sound-dampener is some little doodad; we'll be needing
more of them, I should say."

* * * * *

It was an hour or more later at the Headquarters of the Mountain
Division that the Chief amplified that remark in a way he himself
could not have foreseen. He had been talking to Danny, and now on the
wall of an adjoining room, where men sat at strange instruments, a red
light flashed.

"We still don't know what started it all," the Chief was saying. "But
it made a fine tryout for Morgan's invention. If I thought you and he
could do it, I would believe you had started that fire yourselves for
a"--his voice rose abruptly to a shout--"Man! There's the red on the
board--a general alarm!"

"Throw the big switch!" he roared. "Cut us in, quick! Cut us in!"

Danny O'Rourke, under an