"Ah!" said Simpson. "Well, Number One had its vacuum chamber corroded out a week after we started using dredging. Ran into a vein of stuff with 15 per cent acid content, and it got chewed up something fierce. Number Two sank without a trace—over there in the swamp someplace." He pointed across the black mud flats to a patch of sickly vegetation. "The Mud-pups know where it is, they think, and I suppose they could go drag it up for us if we dared take the time, but it would lose us a month, and you know the production schedule we've been trying to meet."
"So what about Numbers Three and Five?"
"Oh, we still have them. They won't work without a major overhaul, though."
"Overhaul! They're brand new."
"They were. The Mud-pups didn't understand how to sluice them down properly after operations. When this guck gets out into the air it hardens like cement. You ever see a cement mixer that hasn't been cleaned out after use for a few dozen times? That's Numbers Three and Five."
"What about the old style models?"
"Half of them are out of commission, and the other half are holding the islands still."
"Islands?"
"Those chunks of semisolid ground we have Administration built on. The chunk that keeps Control Tower in one place."
"Well, what are they going to do—walk away?"