There were many Diggers, big
shoveling and excavating machines to get
up the ore. There were lorry-like haulers to
transport it to the main work-base. There,
self-powered and movable crushers
reduced it by means of their ponderous
pile-driver arms and loaders flung it into
the barges, which could be picked up by
space-ships. There were also automatic
tenders to supply copper atomic fuel and
lubrication to the other machines.
These Machs—as such semi-automatic
machines were called—had worked
perfectly until now. Their electric reaction-
circuits, which made use of both lens
“eyes” sensitive to light impulses and
electroscopic artificial senses sensitive to
radiation, kept them in their ceaseless
routine of toil. What had interrupted the
carefully-designed routine ?
“Probably,” I told Eek as we swept in
toward Dis, “they’ve run into some
problem that their rudimentary reaction-
circuits can't handle. Well, we'll soon get
them going again.”
I had carefully studied the file on Dis
which Curt had given me before I left. I
spotted, on the drab gray surface of the
little moon, the cluster of cylindrical
barges and sheds that were the main work-
base.
I would not have been surprised to see
motionless Machs around it if something
had gone wrong. But there were no Machs
there at all.
“Now what's become of the Crushers
and Loaders ?” I wondered. “They were
never supposed to leave work-base.”
I landed the space-sled and stepped off
it. Of course, since Eek and I don't breathe,
the deadly poison of the atmosphere
affected us no more than space.
First I glanced into the cylinder-shaped
barges. There was very little actinium,
indicating that no work had been done here
for weeks.
Beyond the barge-docks were the
storehouse for emergency supplies and the
emergency shelter for humans. Since none
of the huge and ponderous Machs could be
in those small buildings I did not
investigate them.
Instead I strode off toward the main ore-
beds, where the Diggers and Haulers were
usually puffing about at their work.
Before I had gone a half-mile I heard a
rumbling clanking sound from ahead.
Only a Mach could make such a sound and
I felt relieved.
“At least some of them are still at work,
Eek,” I said.
Then the Mach appeared over a crest,
coming toward me. It was a Digger, its
huge shovel with its mighty inertron tusk
raised in the air as it rumbled along on its
caterpillar tractor.
It puzzled me to see a Digger wandering
like this. They never were supposed to
leave the ore-beds—the Tenders took
atomic fuel and lubricant to them there, at
regular intervals.
But this one was a mile away from the
ore-diggings. It came clanking along
toward me and I waited. Then the lenses in
its humped circuit-box on top glimpsed
me. It stopped, its atomics purring.
Its reaction-circuits, having received the
visual intelligence that I was human, would
instantly cause it to stand still and await
my actions. The Machs were all made so. I
strode forward to examine it more closely.
Then I got the most terrible shock of my
life. From the giant machine a deep
bellowing toneless voice spoke to me.
It said, “Where did you come from,
chum ?”
I stood stock still. Eek was cowering
behind me in terror. The huge machine
brooded, its lenses pointed straight at me.
It was terribly clear to me what had
happened. My mind, overburdened with
psychoses, had cracked. I was suffering
delusions like the man in the tele-play. I
had thought that the Digger spoke to me.
All this flashed through my thoughts in
an instant. And then the Digger spoke
again.
“What's the matter ? You strip a gear ?”
It was then that I noticed something. It
was a diaphragm set in the front of the