low-level control room. He pressed the call button, and after a few
seconds the face of Lieutenant Cameron moved into the viewing
angle.
“The brass are due in three minutes,” Mills advised. “Everything
okay?”
“Looking good, sir.”
Mills resumed his position by the wall of the dome and noted
with satisfaction the three tracked vehicles lurching into line to
take up their reception positions. Minutes ticked by.
“Sixty seconds,” the duty controller announced. “Descent profile
normal. Should make visual contact any time now.”
A patch of fog above the landing pads in the central area Of the
base darkened and slowly materialized into the blurred outline of a
medium-haul surface transporter, sliding out of the murk, balanced
on its exhausts with its landing legs already fully extended. As
the transporter came to rest on one of the pads and its shock
absorbers flexed to dispose of the remaining momentum, the
reception vehicles began moving forward. Mills nodded to himself
and left the dome via the stairs that led down to ground level.
Ten minutes later, the first reception vehicle halted outside the
Operations Control building and an extending tube telescoped out to
dock with its airlock. Major Stanislow, Colonel Peters, and a
handful of aides walked through into the outer access chamber,
where they were met by Mills and a few other officers. Mutual
introductions were concluded, and without further preliminaries the
party ascended to the first floor and proceeded through an elevated
walkway into the adjacent dome, constructed over the head of
number-three shalt. A labyrinth of stairs and walkways brought them
eventually to number-three high-level airlock anteroom. A capsule
was waiting beyond the airlock. For the next four minutes they
plummeted down, down, deep into the ice crust of Ganymede.
They emerged through another airlock into number-three low-level
anteroom. The air vibrated with the humming and throbbing of unseen
machines. Beyond the anteroom, a short corridor brought them at
last to the low-level control room. It was a maze of consoles and
equipment cubicles, attended by perhaps a dozen operators, all
intent on their tasks. One of the longer walls, constructed
completely from glass, gave a panoramic view down over the workings
in progress outside the control room. Lieutenant Cameron joined
them as they lined up by the glass to take in the spectacle beyond.
They were looking out over the floor of an enormous cathedral, over
nine hundred feet long and a hundred feet high, hewn and melted out
of the solid ice. Its rough-formed walls glistened white and gray
in the glare of countless arc lights. The floor was a litter of
steel-mesh roadways, cranes, gantries, girders, pipes, tubes, and
machinery of every description. The left-side wall, stretching away
to the far end of the tunnel, carried a lattice of ladders,
scaffolding, walkways, and cabins that extended up to the roof. All
over the scene, scores of figures in ungainly heavy-duty spacesuits
bustled about in a frenzy of activity, working in an atmosphere of
pressurized argon to eliminate any risk of explosion from methane
and the other gases released from the melted ice. But all eyes were
fixed on the right-hand wall of the tunnel.
For almost the entire length, a huge, sweeping wall of smooth,
black metal reared up from the floor and curved up and over, out of
sight above their heads to be lost below the roof of the cavern. It
was immense-just a part of something vast and cylindrical, lying on
its side, the whole of which must have stretched far down into the
ice below floor level. At the near end, outside the control room, a
massive, curving wing flared out of the cylinder and spanned the
cavern above their heads like a bridge, before disappearing into
the ice high on the far left. At intervals along the base of the
wall, where metal and ice met, a series of holes six feet or so
across marked the ends of the network of pilot tunnels that had
been driven all around and over and under the object.
It was far larger than a Vega. How long it had lain there, entombed
beneath the timeless ice sheets of Ganymede, nobody knew. But the