The sun sank behind the ground horizon, though at this altitude the sky remained bright for a long time. Finally, night came with its blazing star clouds and gas sheets. Jill talked for a few minutes with Anna Obrenova before going to her cabin. The little Russian seemed warm enough, but there was something in her manner which indicated that she was not at ease. Was she really resentful because she had not been given the first mate's position?
Before going to her quarters, Jill took a long walk through the semipressurized passageway to the tail section. Here she drank some coffee and chatted briefly with some of the officers. Barry Thorn was present, but he, too, seemed a little nervous, even more reticent than usual. Perhaps, she thought, he was still unhappy at being rejected by Obrenova. If, indeed, that had been the cause of their argument.
At that moment, she was reminded that the two had spoken in a language unknown to her. Now was not the time to ask him about that. It was possible she might never be able to bring up the subject. To do so would be to admit that she had been eavesdropping.
On the other hand, she was very curious. Some day, when there were not more pressing things to consider, she would ask him about it. She could claim that she just happened to walk by-which was the truth-and had heard a few words of the dialog. After all, if she did not understand what they were saying, she could not be eavesdropping, could she?
She went to her cabin, where she crawled into the bunk and went to sleep almost at once. At 04:00 hours a whistle from the intercom awoke her. She went to the control room to relieve Metzing, the third mate. He stood around a while, talking about his experiences as commander of the LZ-1, then left. Jill did not have much to do, since Piscator was a very competent pilot and the atmospheric conditions were normal. In fact, the Japanese had set the automatic controls on, though he kept a close watch on the indicator panel.
There were two others present, the radio and the radar operators.
"We should see the mountains at about 23:00," she said.
Piscator wondered aloud if they were as high as Joe Miller had estimated. The titanthrop had guessed them to be about 6096 meters or 20,000 feet. Joe, however, was not a good judge of distances, or, at least, not good at converting distances into metrics or the English system.
"We'll know when we get there," Jill said.
"I wonder if the mysterious occupants of the tower will allow us to return?" he said. "Or even to enter the tower?"
That question had the same answer as the previous ones. Jill did not comment.
"Perhaps, though," Piscator said, "they may allow us to survey it."
Jill lit a cigarette. She did not feel nervous now, but she knew that, when they were close to the mountains, she was going to be at least alittle spooked. They would be entering the forbidden, the tabu, the area of the Castle Perilous.
Piscator, smiling, his black eyes shining, said, "Have you ever considered the possibility that some of Them might be on this ship?"
Jill almost strangled as she sharply drew in cigarette smoke. When she was through coughing, she said, wheezing, "What in hell do you mean?"
"They could have agents among us."
"What makes you think that?"
"It's just an idea," he said. "After all, isn't it reasonable to believe that They would be watching us?"
"I think you have seen more than you're admitting. What makes you think this? It won't hurt to tell me."
"It's just an idle speculation."
"In this idle speculation, as you call it, is there someone you think could be one of Them?"
"It wouldn't be discreet to say so, even if there was someone. I wouldn't want to point the finger at a possibly innocent party."
"You don't suspect me?"
"Would I be stupid enough to tell you if I did? No, I am just thinking aloud. A most regrettable habit, one which I should rid myself of."
"I don't remember you ever thinking aloud before."
She did not pursue the subject, since Piscator made it evident he was not going to add anything. The rest of the watch she tried to think of what he might have observed and then put together to make a pattern. The effort left her head buzzing, and she went back to bed feeling very frustrated. Perhaps he had just been putting her on.
In the afternoon, only two minutes short of the time she had predicted, the tops of the polar mountains were sighted. They looked like clouds, but radar gave a true picture. They were mountains. Rather, it was one continuous mountain wall circling the sea. Firebrass, reading its indicated height, groaned.
"It's 9753 meters high! That's taller than Mount Everest!"
There was good reason for him to groan and the others to look disturbed. The airship could not go higher than 9144 meters, and Firebrass would hesitate to take it to that altitude. Theoretically, that was the pressure height of the gas cells. To go above that meant that the automatic valves on top of the cells would release hydrogen. If they did not do so, the cells would explode, having reached their inflation limit.
Firebrass would not like to take the vessel near the pressure height. An unexpectedly warm layer of air could cause the hydrogen in the cells to expand even more, thus making the ship more buoyant than was safe. Under those conditions, the Parseval would rise swiftly. The pilot would have to act swiftly, pointing the vessel's nose down and also tilting the propellers to give a downward drive. If this maneuver failed, the gas, expanding under the lessened atmospheric pressure, would stretch the cell walls to the rupture point.
Even if the ship got through this situation, its loss of valved-off gas would mean that it would become heavy. The only way to lighten the ship would be to discharge ballast. If too much ballast was dropped, the Parseval would be too buoyant.
Firebrass said, "If it's like this all the way around, we're screwed. But Joe said..."
He stood for a moment, thinking, watching the dark, ominous mass gradually swell. Below them the Valley wriggled snakily, eternally covered with fog in this cold area. They had long ago passed the last of the double line of grailstones. Yet the radar and the infrared equipment showed that thick, high vegetation grew on the hills. One more mystery. How could trees flourish in the cold mists ?
Firebrass said, "Take her down to 3050 meters, Cyrano. I want to get a good look at the headwaters."
By "look" he meant a radar view. No one could see through the massive, boiling clouds covering the mighty hole at the base of the mountains. Bat radar showed a colossal exit for The River, an opening 4.9 kilometers or a little over 3 miles wide. The highest point of the arch was 3.5 kilometers.
The mighty flood rushed straight for 3 kilometers, then tumbled over the edge of a cliff and fell straight for 915 meters, over 3000 feet.
"Joe may have been exaggerating when he said you could float the moon on The River where it comes out of the cave," Firebrass said, "but it is impressive!"
"Yes," Cyrano said, "it is indeed grand. But the air here is almighty rough."
Firebrass ordered the Parseval to a higher altitude and on a course which would parallel the mountain at a distance of 12 kilometers. Cyrano had to crab the dirigible and swivel the propellers to keep from being blown south, and it crept alongside the towering range.
Meanwhile, the radio operator tried to get into contact with the Mark Twain.
"Keep it up," Firebrass said. "Sam'11 want to know how we're doing. And I'm interested in finding out how the Minerva made out."
To the others he said, "I'm looking for that gap in the mountains. There has to be one. Joe said the sun momentarily flashed through a hole or what he thought was a hole. He couldn't see the break, but since the sun never gets more than halfway up the horizon here, it couldn't shine inside the sea unless there's a break that starts at ground level.