MOVED TO @DEGAUSSEUR

"just trust me, okay? it'll be worth it. so you take the speed— in kilometers per second, of course— over c and square that..."

pidge follows obediently, writing out two long trails of digits.

"that's a lot of zeroes," she says.

"it's a fast ship. okay, now plug it into your calculator..."

there's the soft clacking of pidge's fingers typing the equation into her calculator. 

"wait," she squints. "why is it off?"

"why is what off?" he asks, though he can't hide his grin— the one that says I know why, I'm just not telling you.

"the time. it should be ten million. it's ten million and thirty."

lights dance behind matt's eyes like fireflies. "because of special relativity. you remember how I told you about the twins paradox? how if one twin shoots off into space, when they come back, the earthbound twin will be older?"

a second passes. another. when it finally clicks, pidge nearly jumps from her seat.

"we're the twins!"

matt is eight years, eleven months, and twenty three days older than pidge. minus thirty seconds.

they make it to kerberos. matt wonders as the ship reaches its approach velocity if those fifteen seconds come all at once, if pidge back on earth isn't running through a class like an emulator set to double speed. or maybe it happens when they slow down, he thinks maybe he can hear shiro's stretched-out tones as they run through landing procedures as they have a thousand times before. relativity is just that, after all: relative.

they make it to kerberos. they don't make it home.

he tries to keep track of the dilation with the rebels. lose a minute. lose a second. everything becomes twisty with FTL, the mathematical twisting of his equation far easier than the mental twisting he has to do to accomodate to the new circumstances and new allies. but he doesn't spend all his time in his own ship where he can rely on sub-second engine logs; some days he spends aboard vessels that aren't his, stolen from this outpost or that galra cruiser he doesn't entirely understand the nuance of. olia tells him he spent three weeks in a cryopod while his sinews stitched themselves back together after a bad mission, and no one had bothered to log the time or distance of their FTL hops while he was under. he took the average of his weekly time dilation and used that, though the answer always left him unsatisfied. inexact.

he knows this relies on pidge having a consistent velocity. he picks earth, telling himself she must be safe there. it's a comforting thought when the enemy is spotted in the same system as his listening outpost and he flips the switch he prays he never has to flip, the one that shuts off everything but the barest life support; the outpost may be positioned at the far end of a dead system, but it bleeds radiation and rebel transmissions in a way that makes it shine brighter than its pale dwarf star to anyone looking to root out these kinds of stations.

and believe him, there are a lot of people trying to root out these stations.

but the calculus is relaxing. it's relaxing, and more importantly, it serves to keep his mind sharp through the mundanity of a listening outpost. he finds new ways to entertain himself with numbers. he can see the sun from here, so he starts with that— measure the distance from the parallax. use his rebel-provided star charts to find constellations he recognizes on earth, and link them back together to see their strange, malformed shapes from a totally different perspective. orion becomes a giraffe, with an elongated neck and four lopsided limbs. cygnus? now it's a beetle.

he does the math again and again. he tries to lose himself in the numbers. he tries to not think about the fact that for however long it feels like matt's been up here, from earth, it's been longer.

matt is eight years, eleven months, and twenty three days older than pidge. minus seven days, twenty-one hours, and sixteen minutes. he thinks.

matt keeps an eye on voltron.

it's half pragmatism; the rebels need eyes on the defenders of the universe to make sure troops are deployed as necessary, either with or without voltron's backing— sometimes they need cover. sometimes it's about striking somewhere while voltron draws away firepower somewhere else. and while this war has made him a soldier, it's not something that's ever been at his core; matt's rebellion comes at the end of encrypted messages, with colour-coded maps and logs; he compiles data, he watches, he looks for patterns. a war is a puzzle.

pidge tells him they're going after lotor. pidge tells him about the fight. pidge tells him, in an overconfident tone that has become surprisingly like her— the pidge who finds matt is a far cry from the pidge who he knew on earth, but the change isn't an unwelcome one. quite the contrary. he's glad to see her so sure, full of their mother's fire and their father's good judgement— that they're going to stop him, because they're heroes. they have to, right? defenders of the universe.

matt tells her to be careful, because like him, you can never tell pidge not to do something.

voltron goes to fight lotor. voltron does not come back.

matt scrambles with shaking hands and panic screaming up his spine, fighting to keep his tone calm as he outputs for days on all frequencies: where is voltron? has anyone received confirmation from voltron? is voltron still alive?

is my sister okay?

days stretch to weeks.

did I fail her?

weeks stretch to months.

did I fail our parents?

the galra sense this absence and hammer the rebels hard. they're stronger, more voracious now; like an animal with its back to the wall, the empire senses its impending doom and only fights with the sick kind of desperation that can only be found with something coming undone. every line the coalition built is burnt to cinders by sendak and the empire. the blades fall. the rebels do, too. matt's crew of two dozen is reduced to six, and they hide away with the lights off like scared children from the boogeymen.

months stretch to years.

but while he knows the what, he refuses to acknowledge the why. pidge didn't leave a trail. but it's not because she's dead. pidge can't be dead. voltron can't be gone. they need them— they need the defenders of the universe. they're going to lose this war otherwise. she's just busy. she has other priorities. pidge isn't kind enough to leave a trail like matt had because she doesn't have time. he doesn't blame her— can't blame her. pidge doesn't understand what it is to be a big brother, doesn't understand what it is to have your entire being, your beating heart exist to protect another. even when matt was taking his tentative steps into real, tangible rebellion, his every action was guided by a single thought: find me. if shiro is out there, if his dad is out there, if pidge is out there, they'll find him. he hid the clues well, disguised them in math and tricks so deeply ingrained in the holts that only the holts could find them. they had to. they had to.

he looks for them instead in what's missing. places where things should be. the universe is now defined by her absence; so, too, is matt. every instant not spent on the run is spent looking for her.

they find her, eventually. or: she finds them. because of course she does. she always finds them.

when matt sees her again, she's in the hospital, with bae bae giving two loud thumps of her tail as matt approaches. matt pulls his limbs around her and hugs her as gently as he can, fighting every part of him that screams to squeeze and never let go. he lets her talk about the journey through the void, the road trip (he laughs at the name, but it's an expulsion of air, all reflex with no humour), the battle that saved them all. he watches transfixed at her excitement, how even in her darkest moments when they were sure they would die, she burns with the knowledge that they couldn’t. he clenches his fists well below her line of sight until four half-crescents bleed in his palms and tries to not cry.

sitting in this room, watching her body slowly heal beneath sheets and gauze, he wipes away all those calculations of fractional seconds snatched by special relativity. because minutes and days mean nothing when compared to telling their parents that pidge might be dead, to watching his friends and loved ones be taken one by one by the empire in the face of the gaping maw of their absence.