18 "There's something else, sir," remarked Firing
Control, "some of the blocks aren't perfectly square. Some are slightly
taller."
19 "Tell the computer to mark the ones that are slightly taller blue,"
ordered North.
20 In a few moments an image appeared on the screen. "It looks like the
Star Of Spirit," cried North, "but it's a little off cent:er. Why the
two extra blocks at the top?"
21 "It's a marker," answered The Voice. "Remember how we mark north on
a map without writing the letters?"
22 "Of course!" agreed North. "Helm, extend a straight line through the
star going north. Where does it lead?"
23 "It crosses a mountain, sir, here. There seems to be an unnaturally
flat area in the front, here, like a landing zone."
24 "Interesting!" said North. "We'll go down and inspect that ice
first. If it's o.k. we'll use hauling beams to pull it up to the ship.
After that, we'll see what our marker was pointing to. We'll go down in
the buses and the scouts. Signal the rest of the vessels to prepare
their parties."
25 A short time later ten small vessels landed by the great blocks of
ice. Each was ten feet by forty feet at the base.
26 "No way this was a natural formation," North affirmed. "Look! You
can see the impression where other blocks used to sit. This was
definitely a storage area where water that had previously been frozen
into those blocks was stored until it was needed. From those holes in
the cliffs on each side, I think there was a dome over this area."
27 "Quite possible," agreed The Voice. "There's signs of foundations at
the head of the valley and marks