S Morden - One Way

He returned the valves to closed. He shut the panels. He cycled the airlock in the normal way, and went back to sitting at the workbench, propping himself up on a high stool.

Was there another way of dumping the air outside, faster than the trickle that passed through the airlock? The only other possibility was the pump on the first floor.

He spent half an hour trying to break it, make it run backwards, push things into it so that the double baffle that sealed itself would stay open. He couldn’t do it.

Then he went outside with a long, thin piece of tubing culled from a rocket motor, a piece that Zeus had been using to help prototype his steam engine. He found the shielded vent on the outside of the hab, lifted the cover off, and pushed the rod in. He pressed up against the first baffle, and, with considerable effort, managed to break the seal behind it.

Then he pushed again. A brief plume of mist shivered into the Martian air. He bent down and applied as much force as he could manage without bending the pipe. It went in, and stuck. He picked up a handful of dust and trickled it past the outlet. It fell straight down, and then puffed away in a tiny gale.

Frank started the timer on his suit, re-entered the hab, and watched the external pressure reading. The numbers were already falling. It took fifteen minutes to drop to half pressure, and at that point, anyone would have been struggling to breathe normally. It took another thirty minutes for the air to equalize with outside. Forty-five minutes in total, and all it took was a stick.

He retrieved the pipe, remounted the cover, and repressurized the hab.

So there was no way that the workshop had accidentally decompressed. Someone had done it deliberately. The only question was, had Zeus done it to himself, or had someone done it to him?

The mask was on the floor, next to the airlock. The blood that was left in the crevices had dried hard into them, and Frank spent some time scrubbing it out with a black square of parachute. The mask itself was more or less unmodified firefighter’s equipment, working off a pure oxygen tank at the same five psi the habs did. He checked it over without really knowing what he was looking for. Zeus, because of his experience on oil rigs, would have been the expert on this. Frank would have to pull the user manual to check the specifications, but he was pretty certain it wouldn’t work as breathing apparatus at Mars pressure.

He’d done all he could. He still had his actual work to do, tightening bolts and shaking things down, and he’d better get on with that, because he was still on the clock.

He wasn’t going to concentrate, though. The whole situation worried at him. It was more than not wanting to be responsible—though that was a big part of it. Frank needed to know if it was another suicide, because if it wasn’t, they were all in danger.

He picked up the mask, and trudged back to the cross-hab. On his way over, he heard a growl of thunder, and stopped to watch a line of sparks and soot draw itself across the sky. It started in the far east, and arced towards the south. As the incoming object slowed, it grew less obvious to Frank’s eye, and when it disappeared altogether, he turned and climbed up the steps to the airlock, his feet heavy but silent on the metalwork.

Brack was waiting for him, casually leaning against the greenhouse entrance as if one of his team hadn’t just died.

“So what did you find?” Brack pushed himself off the doorway and scooped up the mask. He peered into it, going as far as to sniff it.

“That the hab’s sound. It doesn’t leak. But it can be made to leak if you deliberately sabotage the safeties.” Frank racked his life support and dragged his suit over to the hangers. He swapped it with his overalls.

Behind him, Brack let the mask dangle on its straps. “So what are you saying, boy?”

“Either Zeus deliberately overrode the safeties, or someone else did. It wasn’t accidental.” He started to get dressed, facing the wall.

Brack looked over Frank’s shoulder. “Shut the fuck up, and come with me.”

Frank pulled the overalls up to his waist and gathered the arms around his front.

He walked through to the med hab, and found himself dragged in and slammed against one of the partition walls. The hand at his neck tightened. Brack was right in his face, standing on tiptoe.

“Now you listen here. You better be absolutely one hundred per cent sure about this or so help me God I’m shoving you out that airlock and watching you burn through the little window.”

“The hab is airtight. Pressure stayed up all night.” Frank didn’t struggle, even though he was increasingly uncomfortable. “There’s nothing wrong with it.”

Brack let go, and wiped his palm against Frank’s chest. “So how did you prove that?”

“You can play with the manual valves in the airlock, so that it vents the whole hab outside. It’s difficult and it takes a long time to deflate. The other way is at the pump: you can break the seals from the outside and get the hab to a dangerous pressure in a quarter-hour. Just jam something in the vent.”

“Could he have done it himself?”

“Sure. Same way I did it. But then he wouldn’t have been alive to tidy up afterwards.” That was it. That was what had been bothering him all along. “When I got there, the airlock was normal. I didn’t go round the back to where the pump inlet is, but I was still able to use it to pressurize the hab the same day.”

“Tell me. Tell me straight.”

“Someone depressurized the workshop. They might not have known Zeus was in there. They might not have cared. Maybe they did it deliberately, but didn’t mean to scare him so much that he climbed into the airlock without his suit. Maybe they did want to kill him. Maybe they thought the scuba gear would be enough so he could save himself. Whatever, whoever, they were smart enough to cover their tracks.” Frank’s gaze wandered over to the boxes of medical supplies. “Maybe they drugged him first. Or they knew he was taking drugs, and took advantage of that.”

“Christ almighty, Kittridge. You bunch of lazy, useless fuckups. If it wasn’t bad enough to die in an accident, and commit suicide, now you’re starting on each other.”

“We both know someone’s been in the drugs cabinet. But only you know who that is, right?”

“Maybe I do. Maybe I don’t. I might have exaggerated a little on how close an eye I can keep on you so as to keep you in line.”

“Goddammit, Brack, either you know or you don’t.”

Brack pressed himself forward again, into Frank’s face. “Watch your mouth, Kittridge. Remember I’m the one in a Mars base with four potential murderers.”

Frank, half-naked and consciously vulnerable, couldn’t escape Brack’s closeness. “I know I didn’t do it.”

“You crossed the line once before. Easier to do the second time around.”

“I didn’t do it. Zeus was—” Frank stopped.

“What? He was what? Were you going to say ‘he was my friend’?” Frank could feel Brack’s breath against his skin. “People like you don’t have friends. You got the Mark of Cain, boy.”

“I didn’t kill him.”

“So which one of you did?” Brack turned away, stalking along the length of the med bay and back. “Little Demetrius wouldn’t say boo to a goose. Nature-boy doesn’t leave his Garden of Eden. The pervert? Hell, OK. I’d buy that. He’s got cause to be outside, and he’s a little bitch about his precious power consumption.”

Frank seized the opportunity to feed his arms into his sleeves and jerk his overall up to his shoulders. “The spacesuits have got trackers on, right? Can you use those?”

“When you go out looking for cargo drops, what’s your resolution?”