messages unceasingly as patrols and
firecraft answered the call. Some nearer than himself were reporting
themselves "on the fire"; he saw them grouped in the usual echelon
formation up to windward of the blaze. They darted down and in as he
looked, and Danny thrilled at the sight which had never yet failed to
reach the core of his emotional Irish nature.

The smoke and fire swallowed them up; their red bodies and short black
wings drove unswervingly into the holocaust of flame.

"Like a bunch o' bats out o' hell!" said Danny admiringly. "And 'tis
hell they're goin' into!" Which fact there was none to dispute with
Danny O'Rourke who knew, if any man did, the full truth of the remark.

* * * * *

He saw them as they struck the fire; saw the whirling blast of snow
that drove under them as they went into the fight with the wildest
enemy of man; and he knew that a smothering blanket of carbon dioxide
was driving with hurricane force upon the flames.

On the instrument at his side flashed the "Ascend!" order of the
squadron commander, and an instant later the flight reappeared a half
mile away.

The commander must have sighted O'Rourke's ship. "Shall we repeat over
same course?" the instrument spelled out, while Danny, circling above,
watched the effects of the drive.

It had checked the flames, that first blast of the CO_2 squadron; he
saw blackened, jagged trees where a roaring furnace had been. But the
flames were building up again. "Repeat!" O'Rourke answered; then
watched them drive in again.

From a wooded valley beyond a low range came a call for help. A lone
ship in the red and black of the service had driven down into that
valley that was like a cauldron of seething flame.

"I can't touch it!" a thin voice said. "The up-draft kills my blast."

Danny O'Rourke was sending out another call. The answer came from
powerful sending instruments.

"Nitro squadron Hundred and One, on the fire!" it said, and gave a
position in quick figures. Danny's own voice transmitter was on. He
snapped out the position of the lone fighter. "Get in there!" he
ordered; "Show your stuff! No--wait! Follow me; I'll lead you in!"

And to himself he added: "Now we'll see what pure nitrogen will do in
a real scrap."

He closed a switch, and from a compartment at his back a low whine
rose and grew to a scream. It was echoed in a shriek more shrill from
the bow where a port had opened to take in the air.