“Just to be thorough,” she said and started the compressor going. The blood sample quickly started to fizz and churn as the pressure dropped rapidly, hundreds of tiny bubbles forming in the liquid. Yemec swore, but Susan’s gaze was fixed on the probe’s dial. The needle had flickered and after a moment it began to drop. Susan gasped, picking the dial up and showing it to Yemec.
“The pressure in this base is not four atmospheres. It’s more like seven!” she exclaimed. He blinked stunned.
“How?”
“The storm. The pressure outside goes up, the sphere contracts slightly, the pressure inside increases. Or decreases.”
“But it’s a sphere,” Yemec protested.
“You have pressures outside that turn oxygen into a liquid. You think that can’t make steel lose an inch or two all round?” Catching up, he nodded. “And if the pressure rises or drops in an uncontrolled fashion, someone vulnerable to it – ”
“We have to tell the others,” he interrupted.
“No, we have to get to environmental control.”
“It’s on the way.” He gestured to her to follow and set off in the odd clumsy-footed run that this gravity permitted. She followed at a brisk walk, aware that she was getting older. In the heavy gravity, running was out of the question. By the time she reached the lounge, Yemec was talking to the others.
“-a medical condition? I don’t believe it,” Megah said.
“I’ve seen it. The blood boils as if it had been spaced,” Yemec said, looking to Susan. She nodded and explained.
“Your people are familiar with the damage low pressure does to a body? Well high pressure is just as dangerous. Gas in solution in the blood stream – ”
“This is nonsense. The doctor would have spotted it.”
“Wasn’t he the second victim?” Jayan said quietly. She was staring at the wall.
“Then we need to get the main control to pull us up. But we can’t contact them,” Megah said.
“First we need to get to environmental controls. Adjust it slowly so the pressure lowers to a safe level,” Yemec replied.
“I don’t believe this. You’re going along with her?”
“You got a better idea?” Yemec snapped. He rubbed at his left arm.
“Yeah. We barricade ourself in here and wait. That way they can’t get us.”
“Fine. You stay here. I’m going to fix this on my own if I have to.” He turned and stalked out. Susan took a look at the accusing glares the others turned on her and followed quickly. It was not hard to catch up with Yemec. He was moving more slowly now, muttering to himself.
“This will fix it, right?” he said, looking distracted. He rolled up his sleeve, flexing his arm in obvious discomfort.
“Yes. Are you alright?”
“I’m fine,” he snapped. His throat was red and swollen. Susan looked at the red rash that had come up on his left arm, and said nothing. They walked quickly in silence into the work area, back towards the storage room. For a horrible moment Susan thought he would find the Capsule, but Yemec stopped a little way short of the storage area. He reached up to open the door and fumbled with the handle clumsily before his fingers would close. Angrily, he forced the door open.
Susan looked round. The environmental controls were obvious, the three part mix of nitrogen, oxygen, and helium displayed on gauges. She walked over to the panel, looking for the controls.
“Here,” Yemec swiped a keycard through the console and it came to life. “This is the -”
“- atmospheric controls. Thank you.” Susan blinked at it, trying to remember safe decompression rates for humans. She seemed to remember something like thirty feet a minute, and thirty feet was one atmosphere. Dropping from seven to four would be three minutes by those rules, but she wasn’t sure that was right. She set it to take an hour, with five minute rest breaks at each half-drop. Then she added a second stage, a slower reduction to one atmosphere, taking four hours with steady stops. Yemec watched her, rubbing his forehead in perplexity.
“What are you doing?”
“I’m reducing the pressure slowly. The safety factors on this base should be able to handle a lower pressure long term.”
“Why not just lower it all at once?” Yemec demanded, trying to push her aside. Susan blocked his hand as he reached for the vent lever.
“Because I don’t want to kill everyone on board!” she snapped “You aren’t thinking straight. If the narcosis is caused by nitrogen and helium dissolved in the bloodstream, what happens when you drop the pressure? You saw the sample!”
“I don’t care!” He was stronger than her, but she was between him and the console.
“You will,” she said, hoping he was rational enough to hear her. “Decompression sickness. The gas comes out of suspension and forms tiny bubbles in the bloodstream. What happens if those reach the heart or the brain?”
“You’re trying to kill – ” he said. His eyes were wild and irrational. He had been the most active of the crew. It should not have been a surprise that he was the next one to fall victim. She had to stall him.
“No, you are.” She could see the pressure gauge behind him dropping but nitrogen narcosis was such an individual condition she could not guess at what point he would snap out of it. He stepped back, glaring dangerously, and his hand fell on a metal loading pipe.
“I’m not going to let you kill us!” he snarled. Trapped, with the control pipes behind her, she couldn’t dodge. She screamed as the pipe hit her arm, too fast for her to grab.
“Listen, Yemec -” He brought the bar back over his head and she flinched, raising an arm in defence. There was a blaze of white light behind her eyelids. Cautiously, expecting another blow, she opened her eyes and blinked her vision clear. Yemec’s body was sprawled on the floor, the pipe still in his hand. Behind it a familiar dark shape blurred into focus.
