One Way

24

Brack eventually did his thing of taking the body away. Frank wrapped Dee in parachute cloth, and carried him to the main airlock. What happened to him after that, he didn’t want to see.

The body was still wet. The water would boil out of it as it had done out of Zeus. By the time Brack reached the ship, there’d be a dried husk of a man to bury in the cold Martian soil, lined up next to three others.

How Dee had died was as straightforward as how Zeus had died. Zeus should have been able to get his suit into the airlock with him when he realized that the workshop was depressurizing. Dee should have been able to get out of Comms/Control before suffocating on the CO₂ extinguishers. Neither of them had acted in the obvious way that would have saved their lives.

Had they been doped? It was a possibility. Something in the water? Not the communal water, but something individual, like their spacesuits? Not enough to kill, but enough to make someone too weak to escape whatever fatal scenario the killer had constructed. How was he ever going to prove that? He was now at the point of distrusting not just everyone, but everything. Frank was still in his suit. The air in the habs wouldn’t be replenished for another few hours, and it was either his suit, or in the greenhouse with Zero. And he wanted to be alone. Frank had made sure that Zero’s suit was inside with him, already loaded up with a full life-support pack. Declan was somewhere else in the base.

Frank went back to worrying at the problem. He couldn’t sit down in a regular chair, so he leaned against the door of Comms and tried his hardest to look dispassionately around again, walking himself through the last few seconds of Dee’s life. Answer the radio, twist in the seat, tab up the search screen.

Absolutely nothing that would have involved a power surge or a flashover. Frank walked around the console and arrived back at the door.

The fire alarm sounds. Jump up so quickly the chair spins away across the floor. Run to the door.

This was where Frank didn’t get it. The door, the way out, was right there. Why hadn’t Dee taken it? Why had he—

Frank pushed the door shut.

The door had been shut when he’d found it. Goddammit, Zero.

Both he and Declan had been outside. Only Zero had been inside. If he’d tripped the fire alarm—how?—then had held the door shut while Dee had scrabbled at it, only to realize he couldn’t get through. Then listened for the thump as Dee hit the floor. If Dee had shouted at Zero to open the door, he’d have been taking lungfuls of CO₂-saturated air. It wouldn’t have taken more than a few seconds.

Then run back to the greenhouse and, with the pressure the same both sides, Zero wouldn’t even have to worry about cycling the airlock. Just open the door, step in, close it. He was home and dry.

Not Declan, then.

And the greenhouse had two airlocks. One into the hab, and one that led directly outside, to the back of the base, where he could come and go as freely and unwatched as he wanted. All Zero had to do was collect his suit, as Frank had just done for him, and then re-rack it. He could have used any number of tools from the greenhouse to hold open the valves in the pump, and simply walked back to the greenhouse.

He knew his drugs. The black market prescription drugs, not just the street ones. Crap. That was it. That was the missing link. He was the only person who could have killed both Dee and Zeus.

But why? What was the point of it all? Frank knew why he’d killed: love, the best, purest motive of all. But Zero? Jealousy? Rage? It couldn’t be money or sex, because there wasn’t any money, and as far as he could tell, any sex either. The walls were thin. They could hear each other breathing at night, let alone anything else going on. That left revenge, but Frank couldn’t see that either.

In order to save the rest of them, he’d have to tell Brack. What Brack was going to do with the information was up to him, even though Frank knew what would happen.

Brack would have to make a decision: if that ended up with Zero being kicked out of an airlock without his suit, it’d be just Frank and Declan running the base. How was that supposed to work? Neither of them knew how the greenhouse functioned. At this point, Zero was keeping them all alive even while he was killing them off.

Frank opened the door again, and Declan was standing right there. Startled, Frank raised his hands to ward off an attack that was never going to come, and a moment later, with his arms still up defensively, he felt like a fool.

His shoulders sagged and he stepped aside from the door. Declan edged in, and they stared at each other for a while, saying nothing, only searching each other’s expressions for any clue as to what to do next.

Frank turned off his microphone, and waited for Declan to do the same.

“What’s going on, Frank?”

“Trying to work out who killed Dee and Zeus.”

They didn’t need to touch helmets. There was plenty of atmosphere for their voices to carry through. But it was hard to break the habit.

“You think it was Zero,” said Declan.

“It couldn’t have been you. It couldn’t have been me. We don’t have a lot of suspects left after that.”

“Why would he do that?”

“I don’t know. Maybe he just wants to live alone on Mars, grow his crops, and feed his fish. Makes as much sense as anything else.”

“A couple of things have been bothering me,” said Declan.

“Just a couple?”

“Shut the fuck up, Frank, and listen. Alice.”

“Alice killed herself. Most likely because she could see us starving to death.”

Declan separated contact, and walked around the console, leaning his hands on the desktop. “Did she?”

“There were pills in her hand.”

“Were there any in her mouth?”

“I… I didn’t look. But there were pills, and there was water, and she was dead, Declan. I’m not a cop, but what other answer are you looking for?”

“You found her, right?”

“You were there. I climbed up the ladder in front of you.”

“I was there. I wasn’t there when Marcy died, though.”

“What the fuck, Declan? What the actual fuck? What are you trying to say?”

“Marcy died. You were with her. Alice died. You found her. Zeus died. You opened the airlock door on him. Dee died. First on the scene again. Are you not spotting a pattern here? You think no one else has noticed, Frank? Maybe they haven’t. Maybe Zero’s too stupid, and I’m pretty certain Captain Brack isn’t the sharpest knife in the block, otherwise he wouldn’t be here with us deadbeats. But I’ve noticed. I’ve been watching you for a while now.”

“Because that’s what you do, right?”

“Nothing wrong with turning a vice into a virtue. You haven’t got away with this. Just because we’re on Mars doesn’t mean you can just kill people and walk away.”

Frank looked around. “Walk away? Walk away? There’s nowhere to walk to. Look, I’ve not killed anyone.”

“Well, that’s not true, is it?” Declan started for the door, and Frank blocked him.

“I’ve not killed anyone here.”

“And that’s supposed to be OK, is it?”

“He was dealing drugs to my son.”

“Most people would have just called the cops.”

“He was the cops. The sheriff’s son.”

Declan moved closer and touched helmets. “All I see is a whole lot of bad parenting going on. Now get out of my way.”

Frank pushed him back. “I’m not a killer.”

“Of all the people in this room, hands up who hasn’t killed anyone.” Declan raised his arm. “Anyone else? Anyone?”

“This is serious, Declan.”

“Don’t you think I know that? I’m trapped on Mars with a psycho. And at the moment, the only thing that’d make this whole scenario better would be being trapped on Mars without a psycho.” He wheeled away, and took up his position behind the console again. “I liked you. I actually liked you. I thought we could get on, at least. You seemed to want to treat me like a human being and not some rapo scum-of-the-earth. And Dee looked up to you. He was just a kid. And Zeus: he was easy in your company. Alice? She was difficult to like, but you could respect her. And Marcy was fun, and she was dead before I even got defrosted. Why, Frank? Why? What possible advantage do you think you’re going to get?”

“But I haven’t done anything. It was Zero.”

“Zero wasn’t even out of bed when Marcy died, Frank.”

“Marcy died because her scrubber failed. She died in my arms. I did everything I could to save her, and it wasn’t enough.”

“So you say.”

“And Alice took pills. She checked herself out.”

“That was what it was made to look like, sure.”

They resumed staring at each other across the room.

“Fighting in a spacesuit is a really stupid idea,” said Frank.

“That’s something we can agree on.”

“I didn’t kill Marcy, I didn’t kill Alice. That’s just crazy talk. We know how they died, and it was no one’s fault. No one living’s fault. But Zeus was murdered. Someone deliberately depressurized the workshop.”

“And Dee?”

“They shut him in here. There’s no way he couldn’t make it out the door in time. But if you hold the door closed, he’s got nowhere left to go and nothing else to breathe.”

Declan scanned the console, the hab’s softly glowing walls, the strings of LEDs he’d put up himself. “Do you know what tripped the alarm?”

“No, I don’t know enough about the system. It works off heat, but there’s no evidence of a fire. I just don’t understand how it could have gone off without an actual flame.”

“What is it about you that makes you so incurious?” Declan risked stepping around the desk and used his gloved finger to work his way down through the system’s menus until he could access the fire-response mechanisms. “There. See?”

Frank looked over his shoulder. There was a schematic of the hab, and on-off tabs that could work the cameras. Status bars that indicated the fill level of the CO₂ extinguishers. A manual purge button for each.

“It’s the backup. You can hit the switch and activate the extinguishers if they don’t go off automatically. Probably too late by then—a hab breach will kill a fire stone dead, assuming there’s no oxidizer. You can do this through your tablet. No special controls.”

“Why the hell didn’t XO tell us stuff like this?” Frank stared at the screen.

“Because we’re just the monkeys. We’re not meant to mess with this; this is for the real astronauts who know what they’re doing, and aren’t likely to use the deep controls to try and kill each other.” Declan shuffled around, and was face to face with Frank. “You know, I want to believe you. We knew it was risky. I want to believe that four people dying in a matter of a couple of months is just one of those things. But we both know that it’s not. I’m just going to let Brack handle this. That’s his job, right?”

“You’ve got a problem with that, Declan: I was outside, with you, when Dee died. I couldn’t have held the door shut. You’re my alibi.”

Declan aimed a finger at Frank’s chest. “And you’re mine.”

Frank blinked and turned away, heading out through the door. What if there wasn’t one killer, but two, working together? And they were framing him for everything, deliberate and accidental? The base, where he was, was now literally the worst place he could be. He could feel his heart rate spike, and his skin go cold. He had to get out, the only problem being that the base was it, the single place on Mars that he could live. He’d have to come back at some point.

But he could go to the ship. He could go to the ship and find Brack, and tell him he’d found his evidence. It was his last chance. And he had to do it now, before anyone tried to stop him.

He grabbed a fresh pack from the life-support rack. Then he hesitated. Unless he wanted to wrestle it all to the ground inside the airlock, the only place he could swap packs would be the greenhouse. Zero was in there.

What kind of accident would Frank die in? Would his suit fail him? Would his air fail him? Or had it gone beyond that pretense now? Was it going to come down to shivs and shanks, or a sock full of rocks?

He could just carry it with him, swap it when he got to the relative safety of the ship. Brack had one buggy. He’d have the other. Even if they wanted to chase him, they’d be the better part of an hour behind.

“Hey,” said Zero, a faint disembodied voice. “Who’s that in the cross-hab?”

“Frank,” said Frank. He turned round and saw Zero’s face at the greenhouse airlock window.

“What you doing?”

“Thinking about swapping my life support out.”

“You not got enough?”

“I’m not taking the chance. That OK?”

“Whatever, man. You don’t need my permission.” Zero turned his head so he could peer partway down the connecting corridors. “You going outside?”

“Despite everything, I’ve still got chores to do.”

“Chill. Do it tomorrow. Base isn’t going to fall down because you’ve skipped a day.”

“Maybe it will, maybe it won’t.” Frank started to back towards the airlock that led outside. He had the spare life support cradled in his arms. What else did he have? A nut runner and his tablet hung from his external belt. A pouch of slap-on patches for immediate hab repair. Not anything good in a fight, though the nut runner would make a impromptu blackjack. He needed to tool up. He couldn’t head for the kitchen, because Declan was in that direction.

“You’re not coming in to swap over? I’ll clear the way for you.” Zero’s face disappeared, and Frank darted towards the med bay instead. The boxes of drugs and equipment were still sitting on the shelves. He put the bulky life support down, looked at the labels, then opened one particular box, took out a sealed pack of surgical instruments and slipped them into the same pouch as the patches.

He hoisted the life support again, and rather than go back to the main airlock, left the base through the little-used one in the med bay itself. He felt his suit tighten around him as the air pumped down. He ought to be used to the feeling, but now it felt as it had done at the beginning: claustrophobic and constricting. He waited out the surge of panic, remembering his breathing, closing his eyes and going to his calm place: a brightly lit back-yard, warm from the summer sun, brittle grass underfoot, and the sound of an excited boy splashing around in the new pool. Drops of water glittered in the air, arcing gracefully up, stretching and breaking and shattering on the stone surround.

He was OK. He could do this.

He trotted down the steps, down and across the red sand to the remaining buggy. He slid the life support ahead of him and climbed up, wedging the box between his legs and the seat. He started the fuel cell. No sign of Declan. That was fine. Neither he nor Zero needed to know where Frank was going.

The buggy pulled away, and Frank pointed the front wheels at the distant spire of the ship, just about visible through the surface haze. A trail of dust plumed up behind him, and the wind dragged out what didn’t settle.

It took only a few minutes to cover the distance that would otherwise take an hour to walk.

He pulled to a halt outside the ship. There were empty cylinders, from the things they’d towed there and unpacked right at the start of the mission. But there was no second buggy. Brack wasn’t at the base. He wasn’t at the ship. Frank stood up on the seat and searched the distance for the telltale ribbon of pale dust, but there was nothing.

He got down and walked around the ship, expecting to find the raised cairns of his dead colleagues at any moment, but again, there was no sign. If there was anything that was going to be obvious on the flat landscape of the Heights, it was going to be a cemetery. Maybe, for some reason, it was further away.

He went back for the life support, and climbed the stairs to the ship’s airlock. He’d wait for Brack inside.