down the ramp before they can focus their beams on the airlock."

In the lead groundcar, as the three of them wheeled around and headed
slowly for the north building, Cheng turned to one of his companions
with a frown.

"I've been trying to get through telepathically to Dark, but I can't
reach him," said Cheng. "He didn't give any instructions for getting
into the building, but they seem to have locked these airlocks by remote
control so they can't be operated. We'll have to blast this one as we
did the other one, because I don't imagine Dark will be able to open it
from inside. He seemed in rather a hurry to be picked up."

Dark and Maya hurried up the ramp toward the north building. Dark had
been concentrating too heavily on finding his way through the vats to
receive Cheng's telepathic call.

They passed the barred gate that opened into the corridors of the upper
level, and a few moments later reached the top of the ramp and the gate
to the north building. Dark had been prepared to open this by
telekinesis but, to his surprise, it was already open.

They passed through it and emerged into the north building.

Dark had never seen one of the ground-level buildings in daylight, as
both times he had passed through the south building it had been night.
He looked around the place curiously as they entered.

It was about fifty feet square, bare except for the low, hard bunks on
which the Toughs slept at night. On three sides of it were windows, now
closed with heavy steel shutters. The airlock was across the room,
opposite the ramp entrance. The fourth wall was blank, and apparently
shut off a room at the end, because there was a closed door in the
center of it.

They moved out into the room, and Dark said:

"Slip into your marsuit, and we'll go out the airlock. I told Cheng to
bring the groundcars over this way, and they ought to be ready to pick
us up by the time we get out."

"I don't see why we didn't stay down in the vats until the Phoenix break
in," said Maya. "We were well hidden down there, and there might have
been some way we could have helped the Phoenix from inside."

"Primarily because I'm not sure now that the Phoenix can break in,"
answered Dark. "I didn't know about that heavy emergency barrier the
Masters let down on the south ramp, and I was surprised and relieved to
find they hadn't dropped one on this ramp, too. If they had, we'd have
been trapped below. If they have those barriers on all fou