Nina and Eva entered the rec room together. It had taken each of them several days get get up to speed with their assignments and really understand the work ahead of them. Nina felt confident about her tasks. She was already familiar with networked code and distributed systems. For her it was just a matter of time, but for Eva there were some insurmountable challenges.

"It just doesn't seem fair," she complained. "I came here to learn how to repair and maintain systems just like this, and they give me one that can't be fixed."

"I still don't understand why you can't fabricate something. The Brunel is supposed to be self sufficient."

"Almost self sufficient. Emphasis on the almost. Guess which thing it's not equipped to do?"

"Fabricate a navigation sphere?"

"Well, it is theoretically possible to fabricate one, but they are three metres wide. You would have to dismantle half the ship to get it from the fab bays to navigation. To do that you need a dry dock or an auxiliary support ship, and we don't have either of those."

They found some empty chairs, a challenge in itself between shifts, and sat down. The detritus of an abandoned chess game covered the table. Magnetic pieces sprawled across the chequered table top. Nina absently set up for a new game while they talked. She leaned on her left hand and and moved a pawn on the right of the board forward two spaces.

"So what, exactly, are you supposed to learn repairing a system that can't be repaired? It sounds like a waste of time. You're not learning anything and the Brunel doesn't get any better."

"I asked that same question," said Eva. "They said they understood my frustration, but the Brunel is not an active duty ship, it's a training ship, so it doesn't actually matter if we don't end up with fully working systems. The crew deliberately break things between rotations anyway. The point is to learn how they work and gain the knowledge. At the end of this rotation I'll know the theory of how to make it all work. It's just so unsatisfying to not finish the job."

Eva sighed, and pushed one of her middle pawns forward one space. "Anyway, how is the satellite network? It's something you can actually repair, I hope."

Nina absently slid forward another pawn next to her first.

"Honestly, it's kind of an easy job for me. Once I understood the code base and timing issues they were having, I was able to write new code. I finished it yesterday."

"So soon?"

"There's a planetary science team on board. They want the satellites to scan the surface for something. I can't imagine why. All I see down there is ice. I don't think there's even an ocean under there."

"So what was the problem?"

"No one accounted for atmospheric drag. Or that was the code they deleted. Either way, it's easily fixable."

"Malachi said you were good with code."

"I had an adventurous childhood."

"What's adventurous about sitting behind a computer?"

"The adventures are what got me into trouble. My punishment was supposed to be sitting behind a computer so I would learn something useful. Instead, it opened up a whole new world of trouble."

Eva grinned. "Oh really? How much trouble, exactly?" Using the space created by her pawns, she slid her Queen diagonally to the far left of the board.

"Enough trouble that I had to leave home. How do you think I ended up on the Juggernaut with Mal?"

Eva's grin faded. "You never told me you live on the Juggernaut."

Nina blinked. "Oh, er, that's not what I meant."

"It's what you said."

Nina deflated. "Please don't tell anyone. No one expects us to leave the Juggernaut, and for most of us it's not safe to anyway. People go there to escape, but end up trapped. We got out, but even this is only temporary, I think. If others find out it's going to make things difficult for us."

"For you or for Malachi?"

"For Malachi. He's the real reason we're here. He and his friends."

"Hmm," said Eva.

"Please don't say anything," Nina pleaded. "He loves it here. I can leave but I don't want to ruin his time on board the Brunel. The things he can learn here can really help us back home."

"The passive defences he mentioned," said Eva, remembering their earlier conversation. "So it really is a dangerous place?"

"It can be. Mal's father has built something special there. Something safe. We need to keep it that way."

"And the plumbing?"

"You could say that is a more uh, fundamental issue. Malachi says good plumbing is the high watermark in any civilisation, and, well, we all have needs," said Nina.

Eva laughed as Nina mimed flushing a toilet. "Look, your secret is safe with me, but on the condition you tell me everything. I didn't know anyone could even leave the Juggernaut. If you had the means to leave, why would you ever stay?"

"It's complicated."

"Our shift is over."

"Fine, but let's finish the game first."

"I put you in Checkmate five minutes ago."

"So soon?" Nina examined the board. Somehow she had lost in four moves.

"Stop stalling. Talk."

So Nina talked, and told the story of Malachi's journey so far. In her telling, Malachi was the hero, but she couldn't entirely downplay Tila's involvement, despite her best efforts.

"All of that actually happened? Parador? The pirates? Those ships?"

Nina nodded. "Valkyries, Mal called them."

"But you weren't personally there for any of it."

"Well no, but I found the shuttle. If it wasn't for me, none of this would have happened. I'm not trying to take credit for what they did, but that's the story so far. Tila is on the rescue mission now. Conway arranged for Ellie to join a flight school and Malachi to come here as a thank you. Malachi asked Conway if I could come too, so we could, in Mal's words, learn twice as much. Oh, here he comes. Don't say anything."

Eva shook her head, eyes down, and reset the chessboard.

"Hey Mal," said Nina brightly. "How was the work today?"

Malachi had his hands full. He hooked a chair away from the table with his foot, sat down next to Nina, and dropped three heavy laminated binders on the table.

The chess pieces jumped from the table and snapped back into place as the magnets reclaimed them.

Nina eyes the binders. "I thought you had finished the reading."

"That was the first shelf. This is the second. These binders are the maths of particle emitters. I need to understand this to make sure the tachyon beam is correct."

"What are the other two for if you only have to repair one emitter?" said Eva. She thumbed through the binder and made a face when she saw the pages of dense equations.

"This is for one emitter," said Malachi flatly. "Anyway, setting up the emitter is only one part of the configuration. Chief Hudson forgot to mention that the only way to make sure the system works is the interplay between all three beams."

"What do you mean? I thought they just beamed out into space and that triggered the portal," said Nina.

"That's what I thought too. It turns out that's only the basic explanation. A portal actually needs three beams targeting the same point in space. Three beams at three different speeds; sub, super and luminal. At the point they converge they literally tear space time apart and that's what generates the portal."

"That sounds only wildly dangerous," said Nina.

"It is, but only temporarily. I mean, you remember what happened to the colony ship New Dawn when the portal collapsed. It was twisted inside out. It's scary when it goes wrong, but it's like throwing a stone into a pond. The stone breaks the water surface, it makes a splash, but gravity and surface tension are forces too. The disruption only lasts a moment, so the surface heals. That's what happens to a portal. Space is ripped open but there are more fundamental forces that force it closed."

"You got all that from these manuals?" said Eva. She was impressed. It was her first time seeing Malachi's brain at work.

Malachi continued, his brain sparking faster now it had warmed up. "Like I said, that's just the basic principles. Wait till you hear about particle world line convergence! Did you know that the tachyon beams actually exist in the future?! And—"

Nina touched his arm. "I think that's enough for today. Your audience can only take so much at once."

"It's cool though, right?"

"It is to you, and that's what's important," said Nina, in a playfully patronising tone.

"Okay, point made. But you haven't heard the last of this. If you get to tell me about data vectors, I get to tell you what a heisenberg matrix is."

"Deal," said Nina to his face, but behind her had she stage-whispered to Eva, "Not happening!"

Amusingly unimpressed with his girlfriend's behaviour, Malachi turned to Eva.

"How is the jump navigation project coming along?"

Eva sunk her head into her hands with a glance at Nina. "I don't want to talk about it again."

"Oh, tough day?"

"It literally can't be repaired. That won't look good on my record."

"There's always something. Sometimes you have to think outside the box," Malachi said.

"It's a Brunel-sized box, but you go ahead," said Eva.

"How about you, Nina, How was your first day on the bridge ? Do we have working comms yet?"

"We can transmit okay but we can't receive anything, and when we replay our own transmissions internally its garbled; a mixture of static and digital noise, but another ship can hear them fine. The problem is here somewhere."

"That's not good is it? What if we need to call for help?" said Malachi.

"Mal, these are the training systems. They have full comms with the rest of the Commonwealth if we need it. No one is relying on the bridge systems."

"Oh, right, that makes sense."

"So anyway," Nina continued, "I thought the analogue static might be related to jump navigation, that's also an analogue system, but they haven't even been able to turn their system on yet, so it can't be that." She thought for a moment, tracing imaginary system diagrams on the tabletop with her finger. "My satellites use an analogue carrier code as a backup. It fires periodically as a systems check. Do you think that could be related?" She looked at them both.

"Ooh, maybe. How often does it run?" said Eva.

Nina tapped at her datapad to find the answer. "Every six hours."

"Check that against the logs first thing tomorrow," said Eva.

"Good thinking, thank you," smiled Nina.

"Hey! Problem solved!" said Malachi. He opened the top binder and browsed exploded schematic diagrams of the Cherenkov radiation shield.

"Hardly! There are so many more bugs in that system, Mal. That's just one. We're also picking up weird signals on frequencies not even used in the Commonwealth."

"If they are not Commonwealth frequencies how did you find them?"

"I started with the diagnostic routine. They ran a full-spectrum scan. It stood out as an anomaly in the E-band spectrum, but no one uses that."

"Pulsar interference?" said Eva.

"I checked for pulsars, but it's too strong for that. It must be something local."

"Can you triangulate a source?" said Malachi.

"Not yet, I don't have enough parallax in the signal motion, but if it continues and its moving, I might be able to locate something in a couple of days. Then we can turn the scopes on in and see what we're dealing with."

"Mal, it's like you want to solve this more than she does," laughed Eva.

"Malachi loves a mystery," said Nina. She caught Eva's eye. "Speaking of, Eva's solved a mystery of her own just before you arrived."

"Oh?" said Malachi.

"The mystery of where you two are really from," said Eva. "The Juggernaut."

"Oh," said Malachi.

"Its okay, your secret is safe with me," Eva reassured him. "And your friend's too. I won't say anything."

"Yeah, I don't think Ellie needs anyone knowing the truth on her ship. It doesn't matter for Tila. She's a long way from here. She's part of the rescue mission."

Eva bit her lip. "I heard about the rescue mission. I had no idea it was only made possible because of what you three did. Four," she added, catching Nina's eye. "Do you think they will find the colony ship?"

Malachi closed the binder, and closed his hand around Nina's, and looked Nina in the eye.

"I hope so."

Eva made a worried face. "I just hope your friend Tila is safe."