her. But
stay out of sight of the farm and don't attack until you hear from me. I
should be there within the next forty-eight hours._

The instructions given, the telepathic conference faded out, and Dark
was a solitary man plodding across the desert, pulling a loaded cart
behind him.

He came in sight of the Canfell Hydroponic Farm in just about the time
that he had predicted to Cheng, but waited until nightfall to approach
it. Phobos was abroad in the east at sunset, so Dark waited a little
longer, until the nearer moon plunged beneath the eastern horizon.
Deimos was not in the sky this night, and Phobos' disappearance left it
near pitch-dark.

Dark moved across the starlit desert, pulling his cart, to the walls of
the farm. The farm was not a massive, sprawling fortress like Ultra
Vires, because most of it was underground. The upper floor, in which
Happy's "Masters" lived and worked, was just below the ground level and
the underground vats were below it, extending considerably beyond it in
all directions. The only parts of the farm that projected above ground
were its four entrances, small buildings of white stone, each with its
own airlock.

Dark went through the airlock of the nearest one. These entrance
buildings were the barracks of the Toughs, in which they slept at night,
secure from the possibility of escape because no marsuits were available
to them. Dark had moved quietly through a barracks of sleeping Toughs
the night he had left the farm for Ultra Vires, but this time he had his
cart with him.

There was no alternative but a bold course. Spearing the light of an
electric torch before him, he walked down the aisle toward the barred
gate leading into the regions below, pulling the metal-wheeled cart
across the stone floor behind him.

Its clatter brought the whole barracks awake. On all sides of him arose
an angry growling and shouting, an upsurge from many throats of the
animal noises that were the Toughs' nearest approach to human language.
Dark moved forward steadily, keeping a telepathic "radar" out to warn
him of any impending attack.

The very boldness of his action paid off. Its openness apparently
convinced the Toughs that this was merely another, unusually noisy case
of one of the Masters returning to the farm at night--as Dark sensed had
occurred often before. Dark was not molested.

The barred gate had no controls on this side. Dark operated it
psychokinetically. It raised slowly, he pu