It starts because they've got nothing else to lose.

Pidge is gone. So is Hunk. Allura is sick, and the bones in her cheeks jut out against her skin like fossils under loose dirt. Coran stays with her, keeps her company while she fades away; the castle has started to crumble around them, withering at the corners like loose paper held against flame.

Lance is Shiro's fault. All it takes is one botched pep-talk and a failed training session and Lance locks himself in his room, stolen away from the world and entrenched in his own thoughts.

And then there's Keith.

He's a mess at 30 – a sea of scars and wires and tangled hair. The skin on his legs is rough and charred from an explosion several hundred failed missions ago, and he's missing an arm – just like Shiro, save for the fact that it's cut off after the elbow and not quite as pretty to look at. (So he says, at least.)

But he's still there. When Shiro starts to realize he's losing himself, too, Keith is there to pull him out, to dust him off by the shoulders and push him back into reality.

When Shiro stays up late, staring at the stars, Keith sits next to him. When Shiro disappears into the black lion and pretends to tinker with the wiring under his chair, Keith is outside when he resurfaces to eat, buffing the same small corner of the red lion's paw with a dirty rag.

When Shiro spends eight hours running laps around the castle, lost in a spiral of thoughts that seem to sink further and further into panic with each loop around Allura's closed bedroom door, it's Keith that appears next to him, dressed in full running gear, and keeps him company for another hour.

(It's not until Keith is slowing down, Shiro's pace matching out of subconscious respect, that Shiro realizes the screaming agony in his legs and the cold-burning breath of raw fire on his tongue.)

When Shiro sits down at the table, eats a silent meal, Keith is there, too, reading memos and jotting notes in the margins in his quick, tight handwriting. There are never words. There never need to be.

He's always there. He's always there, until he isn't – and when Keith leaves him, dies in a plume of purple smoke and flame, a part of Shiro's heart - a part he doesn't want to pay any attention to - aches from the feeling of thinking he was worth something more.

"I'm running through the castle's mainframe as we speak, Princess," Coran says, tapping away at a console in the control room.

"You weren't in that room, Coran." Allura's fingers grip the edges of her flight suit. "That… wasn't right. There's something wrong about what's going on right now." She twists her hands. "Very, very wrong."

Coran nods, fusses with the corner of his mustache as the computer catches up with his commands. When it chimes a pleasant tune, he smiles, claps his hands, and turns to face Shiro again. "Well! While that's cooking, we can head back down to the infirmary and get your bloodwork done."

"Considering we're not going anywhere," Allura sighs, looking out the ship's front window, "it's important to stay focused."

"Alright, then," Coran chirps, straightening up. He gestures for the door.

Shiro rubs the back of his neck. "Let's do it, then. Wouldn't hurt anything to be sure."

The lights running along the floor of the castle's hallways flicker and twitch as they pass, as though triggered by some sort of hidden tripwire. Shiro takes each step with ginger care, worried that even the slightest movement out of place will send the room back into dark and ominous shadow.

"I've managed to isolate the power systems controlling the lights," Coran says from ahead of him, as if having read his mind. He frowns. "Life support, though, is still another story. Hopefully we can get moving again, and soon – otherwise we're going to run out of air fairly quick."

"How quick is quick?" Shiro asks. His stomach churns.

Coran makes a show of tapping out a series of numbers on his fingers. "I believe," he says, "eight of your Earth days, I think."

Shiro blinks. "It's that bad?"

"The castle has been dormant for a very long time," Coran says. "There are many things I haven't had the chance to repair yet – several parts of the castle are barely working at all. It's a miracle this old girl lifted off the ground in the first place."

Shiro winces. "About that."

"Oh, pshh," Coran says, waving a hand. "You don't know why that happened any more than we do. This old tech does some strange things when you let it sit for long enough." He shrugs. "If the castle wanted to use you to take off, there isn't much you could've said that would have convinced it to do otherwise."

"That's not exactly reassuring, Coran."

Coran shrugs again, stopping at a closed door in the middle of the hallway. When he raises his hand, taps a button on the console in the wall, it slides open. "As for why the castle decided to single you out over everyone else, however," Coran says, stepping inside and looking over his shoulder, "we can figure that out ourselves. Doesn't solve our problems, but it does answer some questions."

The room wakes from a restless slumber the moment Shiro steps inside, the light panels on the walls flickering on with each hesitant footstep. This medical room is different from the one with the healing pods – there are rows of specialized machines and measurement devices and a shelf stacked from top to bottom with test tubes and vials and locked, official-looking, white boxes.

Shiro remembers this room, if only vaguely. It was where Pidge had set up shop, all those years ago, stringing wires and cabling through the walls and connecting the rest of the castle up in a grid of machinery and controls that not even Allura understood. It's nearly unrecognizable in this form – a simple office with musty air and empty chairs.

"I don't exactly know what I'm doing," Coran says, poking at a large syringe sitting on the counter next to an operating table. "I suppose it won't hurt all that much."

"That's fine, Coran," Shiro says, watching the man play champion and puff out his chest in faux gravitas. He reaches over with his metal arm, grabs the familiar Altean device, pulls a clean test tube from an opened crate nearby.

"What?" Coran says, eyes bulging. "Are you just going to—"

Shiro stabs the needle of the syringe into the skin of his flesh arm. The vial turns a healthy shade of red. "How much do you need?" he asks, watching the tube fill with each pump of his heart.

Coran winces. "That should be enough," he says. "Don't need to drain yourself dry, now."

The needle comes free just as easily as it had entered, and he hands it off to Coran, grimacing, twisting the flesh around the open wound.

"Alright then," Coran chirps, striding across the room to a wall of displays and screens and sensors Shiro never bothered to understand. "It may be a while before we know anything, but I'll make sure everything's in order."

The ship sits silent around them, walls uncracked and unmarred and untainted with a history Shiro isn't excited to relive again. But there's also a promise in these walls – a promise that maybe something different could happen. That things could be better now.

Shiro is scared of the silence, because with the silence comes unwanted thoughts.

"Coran?" Shiro asks before he's realized it, voice small. He clears his throat.

"Yes?"

He stops, has to think of a question, but when one forms on his tongue, he realizes it was always there. Has always been there.

"What do you think is going to happen next?"

Coran stops fiddling with the centrifuge-like machine and turns on his feet, fixing Shiro with a curious stare – something far too serious. "That's the question, isn't it?" he asks in kind. "We could very well be forced into battle with the Galra."

"Or?" Shiro asks.

"Or, we could end up stranded out here in the middle of space," Coran says, still smiling in that far-off way. It's uncanny. "And die."

"I'd prefer for that not to happen."

"I'm sure," Coran says, winking.

Shiro frowns. "But… I'd also prefer for the alternative to not happen, either."

"Sometimes we don't have that luxury."

Shiro swallows. "Sometimes we do."

"Actually, the castle's systems aren't too difficult to interface with," Pidge is saying when Shiro returns to the common area, laptop propped against her raised legs. She lifts it with a pinky finger. "You guys are really lucky I managed to bring this thing with me."

"Honestly, Pidge, if anyone could have figured out how to do it without a computer, it'd be you," Lance says, with startling honesty. So much so, it seems, that it startles him, too.

"Wow," Pidge says, blinking wide behind the rims of her glasses. "Thanks, Lance. Genuinely."

"Sometimes he forgets what the difference between thoughts and speech is," Hunk tells Allura, who nods understandingly. "We're lucky this time it wasn't something gross."

"Hey! I'm more than capable of being a polite gentleman." Lance puffs up his chest. "Isn't that right, Princess?"

Allura blinks, leaning toward Hunk. "You're right. We are lucky."

Keith is the first to notice Shiro's return. He stands in one motion, pushing away from the couch as if shocked. "How'd it go?" he asks. It must have been the first time he'd spoken in some time, because the rest of the room turns to watch.

"Fine," Shiro says. He rubs behind his head, wincing through a fake smile. "Coran's running the blood as we speak."

Keith holds eye contact for a heartbeat, two heartbeats, then flinches. He doesn't say anything else. Maybe he'd forgotten to think of something else.

"We're in the process of trying to diagnose the ship's computer," Pidge says. "Allura's been helping me figure it out, but it's slow-going."

"We're making progress," Allura says, smiling in the pinched-off way Shiro knows means she's uncomfortable. So they weren't getting anywhere, then.

"Can I help?" Shiro asks, stepping into the room, pressing his hand into Keith's shoulder as he passes. The motion is instinctual – something benign and thoughtless and borderline accidental. They both freeze at the contact, sharing a hasty glance before Shiro peels himself away, moving just that much faster.

Not now, Shiro tells himself. Not yet.

"Not really," Pidge says from over the rim of her glasses. "Unless you all of a sudden understand complex crystal matrix memory storage algorithms."

Shiro smiles. "Sorry, I'm fresh out of that."

"Well, he was flying this ship around like a fighter jet just a few hours ago," Hunk says. "And before that, he piloted the blue lion to get us here in the first place. Maybe he knows something, but just doesn't know it yet."

"That doesn't make any sense, Hunk," Lance says.

"No." Allura stands. "That does make sense. A lot of the castle's functions are performed through a link to the pilot's quintessence." She reaches across the couch and grabs a glass tablet, half-hidden behind Lance's thigh. "Maybe try this?"

Shiro takes the tablet after Allura yanks it away and ignores Lance's yelp of surprise. "I don't really know what to do with this."

He never had very good luck with learning the Altean language. Well, no – that's a lie. What little he'd understood he understood well, but the time restrictions from constant battle forced him to compromise. When Allura hands him the tablet, shows him how to turn it on as though he didn't already know the way by heart, he tries his best to hide his shock from how much he did remember. He slides into an empty seat on the smaller couch across from the others, letting his mind wander.

"So what about that whole 'not dying from asphyxiation' thing?" Hunk asks, once Allura settles back down into her previous seat and leaves Shiro to his own devices. "How's that coming along?"

"We're working on that, too," Pidge says, not looking up. "Trying to kill two birds with one stone here."

"I'm sorry," Allura says. "'Birds'?"

"Flying things. Small. Have feathers." Pidge shrugs, fingers still dancing across her keyboard. "You know. Birds."

"Fascinating," Allura murmurs.

"Earth is full of all sorts of fascinating stuff," Lance says. He leans back on the couch, props up a leg on his knee. "You'd probably really like it."

"I'm sure I would," Allura says.

"The food? To die for." Hunk smiles a dopey smile. It falls off his face as quickly as it'd appeared, twisting into something crestfallen and realistic and far too painful for Shiro's peripheral vision to handle. "Well. That's not to say I've tried much else outside of Earth, but you know what I mean."

"Allura," Pidge says, "what in the lower levels of the ship might draw a prolonged amount of power?"

Coran answers in Allura's stead, reappearing in the doorway. "If it's not the engines, then maybe the shield generator?"

"The shields, if I've read this right" –Pidge buffs a scratch on the surface of her screen with the fabric of her long sleeves— "don't run at full power all the time, only when they're needed. And the engines weren't running, either."

"How long of a time frame are we talking here?" Keith asks, voice quiet.

Pidge puffs out her cheeks, letting the air in her lungs escape with one violent huff. "I don't understand the Altean time system, so I can't be sure, but it looks like a long time."

"Days?"

"Thousands of years."

"Sorry, what?" Coran asks.

"Thousands of decaphoebes," Shiro translates absentmindedly. He continues to poke at his screen, only looking up when he realizes nobody else is talking.

They're all staring at him.

"How did you know that?" Lance asks.

"I don't know," Shiro lies. "Just came to me."

The power dies again in a whir of failing machinery.

The lights running along the walls vanish, leaving the room half-baked in the lime-green glow of Pidge's computer screen. Altean characters flash across the surface of her glasses until she props the laptop display backwards and forces it forward, letting its light fall over the rest of the group.

"What now?" she says. "Can't access the computer while it's down like this. I'm probably going to have to start all over again, too, once it reboots."

"What are you saying?" Keith asks.

"I'm saying," Pidge says, "that we're back at square one."

Something moves across the room. It's a rustle – a tremor in the back of Shiro's mind, something that trickles down his neck and pools somewhere on his spine.

There's a light. It's a flash, a flicker, the whiff of a candle before it's blown out. It's blue, like stardust, suspended in the darkness of a powerless castle. It's there, in front of the common room door, filling the space Coran had just been in.

It moves. Pidge's laptop screen flickers.

"What?" Lance mutters. "What is that?"

Shiro's gut stiffens. The temperature in the room drops. The light disappears, vanishes, reappears three feet closer. Strips of blue peel away from the center like glitched paper, fade into a cloud of icy dust.

The castle's lights flash on for a moment, and the ventilation fans – what few of them Coran had managed to get working on emergency power – spool up with a mechanical whine inside the walls. It's trying. The castle is trying.

But it's dead again another heartbeat later, another breath. The ship stays cold and silent. The thing is still there, hovering in perfect stillness, looking like a tear in the fabric of reality.

"What are you?" Allura says, her voice piercing the darkness despite how much it shakes. "What do you want with us?"

The thing does nothing.

"It looks like a cloud," Pidge says. "A glitched-out cloud."

Silence. The ship is eerie when silent, like a piece of space folded in on itself. It's unnatural. Uneven. Incorrect.

The cloud moves again, disappears and reappears six inches from Shiro's face.

The room erupts into shouting. Shiro doesn't flinch.

There is something odd about the cloud. It doesn't fear him. It looks at him out of a sense of curiosity, a sense of surprise, almost as though there is something wrong with Shiro and not the other way around. There's a thought swirling around the center of the cloud's mind, a thought that says there's been a mistake. That this wasn't supposed to happen. That there was a problem, things weren't supposed to go this way, why was he here and not—

He only realizes after Allura's hands light up silver-blue in dormant Altean rage that he's crumpled to his knees, breath coming out in sharp bursts.

"Get out of here," Allura seethes through a gap in her clenched teeth, face covered in inverted, self-made shadow. Her hands warp the air around them, magic as hot as her stare, as blue as the cloud.

The same blue as the cloud.

The lights come back on. The ventilation fans whir back to life. The heat starts to return to the corners of the room. The seven of them are all still, shell-shocked, frozen on their seats. Shiro lets his backside fall flat on the floor.

The cloud is gone.

There's a heartbeat where nobody says anything. Another heartbeat where they all unfold, unclench, resort themselves on the couch. Remember to breathe. There's more silence, but this time, it's right. It's natural.

"Nice work, Allura," Coran says. "That thing was really giving me the quibblies."

Allura's eyes are wide, and she's still staring at the spot on the floor in front of Shiro's crooked, prostrate body as if the cloud were still there. "I didn't do any of that," she says, voice quiet, still unmoved. "It left on its own."

Lance leans forward, the crease in his brow far too familiar to the old Lance from Shiro's past. From Shiro's future. "Allura?"

"I couldn't stop it," she whispers. "It was Altean magic, whatever it was. And I couldn't stop it."

Shiro decides a walk is the only thing that would keep him sane, but halfway down another unblemished corridor and through another unjammed door, he starts to realize maybe that was a bad idea.

He finds himself in a quieter part of the ship, where the lights grow dim. The lion hangars each stretch off in different directions in front of him, offering him a choice – a choice on which he can't concentrate.

So he slides to the floor, lets his back press against the wall, forces the crown of his head against the cold, alien metal like it might swallow him up and let him forget where he was or what was happening.

This was painful. This hurt. Seeing everyone again is another thing, but there's a feeling caught in Shiro's throat that makes him suspect all of this is his fault.

"Hey."

Shiro opens his eyes, unaware he'd closed them in the first place, and pivots his head just enough to see Keith standing there, arms crossed over his jacket and burning a hole in the floor with his stare.

Shiro smiles. "Hey."

Keith goes through the motions of internal conflict in only the way he knows how, with clenched fists and furrowed brows and hesitant silence. Shiro watches him out of the corner of his eye with a fond sense of understanding, lets Keith work up the nerve himself, does nothing more than press his back against the wall and wait.

Finally: "Can I join you?"

Shiro opens an eye and smiles wider. "Yeah."

Keith's footsteps are damn near silent. He settles against the opposite wall, folds his legs up halfway to his chest, props his wrists against his knees and pretends to pick at a sliver of invisible thread between his fingertips.

"So," Shiro says.

Keith's jaw knots. "So."

Shiro closes his eyes again, letting the quiet hum of the castle soothe him through their shared points of contact. His mind wanders, splits into four parts, and he's sitting there, lost in his thoughts, when Keith speaks again.

"You're ignoring me," Keith says. It's not an accusation, nor is it a question. It's a fact. Like the weather, or like their circumstance.

Shiro opens his eyes. Keith still isn't looking at him.

"I'm not ignoring you." It's a lie. They both know it. "It's complicated," Shiro adds instead.

Keith is silent. Shiro swallows around the lump in his throat and sighs.

"It's not your fault," he says. "This is my problem. I need to fix it."

"Why are you always treating me like a child?"

Shiro freezes.

"You don't trust me," Keith continues, pushing himself back to his feet. "Something happened after you disappeared. Don't do this to yourself, Shiro. Don't shut me out."

"I'm not trying to shut you out," he says, scrambling upright, gripping the corner of the hallway with a mechanical hand to steady himself. "It's complicated. I need time."

Keith stops mid-stride. "Why?" he asks. "Why does it take time to decide whether you need my help? Whether you want my help?"

A bubble of anger – no, of frustration – crawls its way up Shiro's throat. "Because I'm not the Shiro you think I am," he says, voice sharper than he had planned. The words leave an unpleasant taste on his tongue; they're the first thing from this world that feels the most like the old one.

Keith turns around. His expression makes Shiro ache. "I don't care," he says. "Don't you get it? I don't. You left. Now you're back. What difference does it make what happened in between?"

Shiro narrows his eyes. "Keith."

"I know," Keith says, wincing. "I know. I just…" He runs a hand through the fray of his hair. It's shorter – shorter than it was before. Shorter than it would be in the future. The not-future? Shiro winces, too, nearly misses the next words out of Keith's mouth. Figures – he's given the chance to do everything over, and he still fixates on the past. "I missed you."

Whatever remained of Shiro's frustration evaporates, leaves him through his toes, sucks him dry of whatever energy he had left. Now, he's just tired. So tired.

"I missed you, too," Shiro says, quietly, and watches Keith leave.

"We've got something," Hunk says the moment Shiro steps onto the bridge. He's standing off to the side, arms crossed, expression marred with something short of nerves.

The lights are still dim, and the consoles are still offline, but Pidge has apparently taken up residence at an empty station and propped her laptop across the dead Altean computer screen. She's not using it, though. She's not in the room at all.

"Where's Pidge?" Shiro asks, spinning in a loose circle, trying to see if he'd missed her somewhere.

"She's, uh, running back to the common area," Hunk says. "She needed to get something."

"And the others?"

"They're with her."

Shiro looks around the room. "Alright, then. What have you found?"

"Something in the ship," Hunk said. "It's a synthesizer of some kind. Kinda like the computer from Star Trek? But instead of making 'tea, earl grey, hot', it's doing something else."

"And you think that's what's causing that" – Shiro gestures vaguely – "cloud?"

Hunk scratches his forehead. "It's the best lead we've got right now."

"So that's why Pidge is gone?"

The doors open.

"No," Pidge says, holding a familiar tablet in her hands. Allura stands behind her, skin white as a snow. She's staring at Shiro, looking at him like he didn't exist. Like he shouldn't exist.

"What's going on?" Shiro asks.

"I wanted to get your tablet," Pidge says. She fidgets in place. "I figured maybe you had something interesting on there? That maybe you'd figured something out?"

"Do you really think Shiro could have done something like that?" Hunk asks. Shiro looks at him, and he shrugs. "Sorry. Didn't mean it to come out that way. But you know what I mean."

"Honestly, no," Pidge says, stepping into the bridge. She shoots Shiro an apologetic smile. "No offense."

"None taken," Shiro says, watching Pidge slide into her seat. "I don't know the first thing about Altean tech."

"Yeah?" Pidge says, spinning around until she's pointed at him. She arms herself with the tablet, turns it on, points it outward. "Then why is it you wrote two hundred lines of the castle's base code in perfect Altean? And why does it just so happen to be exactly what we need to get the castle working again?"

Author's Note:

Thank you for reading!

As always, thank you so much to my beta, MaethoMixup. Her link is in my profile.

Come say hello on Twitter! My username is EndoWrites.