t, leaped into one of the cars and started the
engine.

The door from the house shattered and Quest burst through. The two
guards turned and fired together.

He could be hurt by bullets. He was staggered momentarily.

Then, in a blur of motion, he sprang forward and swept the guards aside
with one hand with such force that they skidded across the floor and lay
in an unconscious heap against the rear of the garage. Trella had opened
the door of the car, but it was wrenched from her hand as Blessing
stepped on the accelerator and it leaped into the driveway with spinning
wheels.

Quest was after it, like a chunky deer, running faster than Trella had
ever seen a man run before.

Blessing slowed for the turn at the end of the driveway and glanced back
over his shoulder. Seeing Quest almost upon him, he slammed down the
accelerator and twisted the wheel hard.

The car whipped into the street, careened, and rolled over and over,
bringing up against a tree on the other side in a twisted tangle of
wreckage.

With a horrified gasp, Trella ran down the driveway toward the smoking
heap of metal. Quest was already beside it, probing it. As she reached
his side, he lifted the torn body of Dom Blessing. Blessing was dead.

"I'm lucky," said Quest soberly. "I would have murdered him."

"But why, Quest? I knew he was afraid of you, but he didn't tell me
why."

"It was conditioned into me," answered Quest "I didn't know it until
just now, when it ended, but my father conditioned me psychologically
from my birth to the task of hunting down Dom Blessing and killing him.
It was an unconscious drive in me that wouldn't release me until the
task was finished.

"You see, Blessing was my father's assistant on Ganymede. Right after my
father completed development of the surgiscope, he and my mother blasted
off for Io. Blessing wanted the valuable rights to the surgiscope, and
he sabotaged the ship's drive so it would fall into Jupiter.

"But my father was able to control it in the heavy atmosphere of Jupiter,
and landed it successfully. I was born there, and he conditioned me to
come to Earth and track down Blessing. I know now that it was part of
the conditioning that I was unable to fight any other man until my task
was finished: it might have gotten me in trouble and diverted me from
that purpose."

More gently than Trella would have believed possible for his
Jupiter-strong muscles, Quest took her in his arms.

"Now I can