otted), the Hans
did have some very highly sensitive sound devices which operated with
great efficiency in calm weather, so far as sounds emanating from the
air were concerned. But the "ground roar" greatly confused their use of
these instruments in the location of specific sounds floating up from
the surface of the earth.

This ship must have caught some slight noise of ours, however, in its
sensitive instruments, for we heard its electronic devices go into play,
and picked up the routine report of the noise to its Base Ship
Commander. But from the nature of the conversation, I judged they had
not identified it, and were, in fact, more curious about the detonations
they were picking up now from the Bad Blood lands some sixty miles or so
to the west.

Immediately after this ship had shot by, we took the air again, and
following much the same route that I had taken the previous night,
climbed in a long semi-circle out over the ocean, swung toward the north
and finally the west. We set our course, however, for the Sinsings' land
north of Nu-yok, instead of for the city itself.

CHAPTER XII

The Finger of Doom

As we crossed the Hudson River, a few miles north of the city, we
dropped several units of the Yellow Intelligence Division, with full
instrumental equipment. Their apparatus cases were nicely balanced at
only a few ounces weight each, and the men used their chute capes to
ease their drops.

We recrossed the river a little distance above and began dropping White
Intelligence units and a few long and short range gun units. Then we
held our position until we began to get reports. Gradually we ringed the
territory of the Sinsings, our observation units working busily and
patiently at their locators and scopes, both aloft and aground, until
Garlin finally turned to me with the remark:

"The map circle is complete now, Boss. We've got clear locations all the
way around them."

"Let me see it," I replied, and studied the illuminated viewplate map,
with its little overlapping circles of light that indicated spots proved
clear of the enemy by ultroscopic observation.

I nodded to Bill Hearn. "Go ahead now, Hearn," I said, "and place your
barrage men."

He spoke into his ultrophone, and three of the ships began to glide in a
wide ring around the enemy territory. Every few seconds, at the word
from his Unit Boss, a gunner would drop off the wire, and slipping the
clasp of his chute cape, drift down into