another way out than by finding an enemy parasite."

"Where do you think these insect invaders came from?" asked Larner.

"You have noticed they are unlike anything you have on earth in
anatomical construction," said the savant. "They partake of the general
features of Coleoptera (beetles), in that they wear a sheath of armor,
yet their mouth parts are more on the order of the Diptera (flys). I
regard them more as a fly than a beetle, because most Coleoptera are
helpful to humanity while practically all, if not all, Diptera are
malignant.

"As to their original habitat, I believe they migrated here from some
other planet."

"They could not fly through space," said Larner.

"No, that is the mystery of it," agreed Zorn. "How they got here and
where they breed are the questions that we have to answer."

* * * * *

Long days passed on Venus. Long days and sleepless nights. The big
insects were hunted nightly by men armed with ray-guns, and nightly the
blood-sucking monsters took their toll of humanity and animals.

Finally Larner and Zorn determined to capture one of the insects alive,
muzzle its lance and suction pad, and give it sufficient freedom to find
its way back to its hiding place. By following the shackled monster the
scientists hoped to find the breeding grounds.

All the provinces of the planet joined in the drive. Men turned out in
automatic vehicles, propelled by energy gathered from the atmosphere.
They came on foot and in aircraft. Mobilization was at given points and,
leading the van, were Zorn and Larner and their confreres in the targo
of Nern and Tula Bela. The great army of Venus carried giant
searchlights and was armed with deadly ray-guns.

* * * * *

Headquarters of the vast Army of Offense was in the targo of the Belas.
Larner was in supreme command. Just before the big army set out to scour
the planet to seek the breeding place of the monsters Larner issued a
bulletin that set all Venus by the ears.

Addressed to President Vole Vesta of the Republic of Pana and the good
people of Venus, it read:

As is generally known, it has been the habit of the nation's
space-flying merchantmen to visit the sunlit side of the planet
Mercury to obtain certain rare woods and other materials not found
on this planet.

One side of Mercury, as is known, is always turned from the sun and
is in a condition of perpetua