a squat, gleaming creature with the symbol M-11 etched
across its rotund chest, and deactivated it by the simple expedient of
pulling from its socket the line running from the capacitor unit in
the lower trunk of its body to the maze of equipment that jammed its
enormous chest. The instant M-11 ceased functioning, the other two
servomechs were automatically activated to cover that section of the
controls with which M-11 was normally integrated.

This was overloading their individual capacities, but it was an
inherent provision designed to cover the emergency that would follow
any accidental deactivation of one of them. It was also the only way
in which they could be checked. You couldn't bring them outside to a
lab; they were _hot_. After all, they spent their lives under a
ceaseless fusillade of neutrons, washed eternally with the deadly
radiations pouring incessantly from the pile whose overlords they
were. Indeed, next to the pile itself, they were the hottest things in
the plant.

"Nice job these babies got," commented Gaines as he checked the
capacitor circuits. He reactivated the servo and went on to M-19.

"If you think it's so great, why don't you volunteer?" countered
Sokolski, a trifle sourly. "Incidentally, it's a good thing we came
in, Joe. There's half a dozen units here working on reserve
transistors."

Their sporadic conversation lapsed; it was exacting work and they
could remain for only a limited time under that lethal radiation.
Then, almost sadly, Gaines said, "Looks like the end of the road for
M-75."

"Oh?" Sokolski came over beside him and peered through the violet haze
of his viewing glass. "He's an old timer."

Gaines slid an instrument back into the pouch of his suit, and patted
the robot's rump. "Yep, I'd say that capacitor was good for about
another thirty-six hours. It's really overloading." He straightened.
"You done with the board?"

"Yeah. Let's get outta here." He looked at his tab. "Time's about up
anyway. We'll call a demolition unit for your pal here, and then rig
up a service pattern so one of his buddies can repair the board."

They moved toward the door.

* * * * *

M-75 watched the two men leave and deep inside him something shifted.
The heavy door closed with a loud thud, the sound registered on his
aural perceptors and was fed into his analyzer. Ordinarily it would
have been discharged as irrelevant data, but cognizance had wrought
cer