Bertl is six and he picks up a bird, fluttering broken-winged in the path. The bird tries to struggle away, but he only means to help, really he does, and he cups his hands gently as he carries the fragile body home. The bird cries, flapping a little with the unbroken wing. Bertl shushes, petting the soft-feathered head a little with his thumb, and after a while it goes still.

He has a little box with a scrap of worn-out blanket. He puts the bird in it, and waits.

The bird doesn’t move, and after nearly an hour of silent watching he realizes that it died while he held it.

Annie tells him that he killed it. Annie knows these things. She lives with her father out past the edge of town, almost in the wilds of the mountain itself, and she knows about animals. She tells stories when they walk together, read from subtle signs on the ground and in the trees that Bertl doesn’t notice until she points to them. Annie is wise, in a way that Reiner isn’t and Berik is a little and Bertl only wants to be. Bertl likes walking with her, likes the things she says and likes turning them over in his mind.

“I wanted to help,” he says, not quite comprehending.

“A bird can’t know that,” Annie says, in the voice she uses when something is very simple and Bertl should have thought of it himself. At least, that’s what he thinks it means. “You’re so big, it died of fright.”

Bertl is seven and he knows the adults don’t like him. He sees the looks they give him when he breaks and cries, when he lets fear get the better of him, when anxiety or inattentiveness make him fail a task. He can’t help it, he thinks, but he also knows that’s not good enough, that he needs to help it.

He also knows that doesn’t help, that he can’t do things in the way they want him to and he doesn’t know any other. They sigh, and curse, and put their hands on their faces, and tell him to hide behind Reiner if things gets bad. It isn’t as if he’s good at anything else.

“The degenerate son of a great line,” they call him, when they think he can’t hear — or maybe because they know he will. He can’t help it. He wants to do better, wants to make them proud, wants — anything, anything, just once, a pat on the head or a word of approval like Reiner and Annie and Berik get, just something to prove he isn’t worthless.

He gets nothing.

Bertl is eight and Reiner is broken, crumpled on the ground with his leg twisted beneath him. He said that branch would hold and it didn’t. There is blood and everything is wrong and Bertl’s head is spinning, he is crying, he can’t breathe.

Everything is wrong, and then suddenly everything is clear. He is still crying and he still can’t breathe, but he knows what he needs to do.

He moves without feeling and only gags a little as he drags Reiner’s leg straight, feeling the snapped edges grind together. He doesn’t hear Reiner’s whimper, doesn’t see him clutching at the ground or the tears that drip down his cheeks. He makes the leg as straight as he can so it can heal, steam hissing where the sharp edge of bone broke through skin.

He blinks and Reiner is patting his face and shoulders worriedly, brushing pine needles off his shirt. “ — okay?” he is asking. “Bertl, are you okay? Wake up.”

He collapses, hugging Reiner’s chest, and the heartbeat under his head is strong and steady. He clings, trembling, until Reiner picks himself up and grips Bertl’s hands tightly and walks them both home. He is afraid, so afraid, because when Reiner fell he saw for a moment a broken-winged yellow-feathered bird in place of a boy, and he has only just realized that the people he loves can be fragile.

There are three people in the world who look at him like a person and not a tool, and he is terrified of losing them.

Bertl is nine and the birds have gone silent in the trees. If he were Annie he would know to be wary, but he is not. He only wonders at it, and then a Titan is charging and he cannot move until Berik shoves him and Reiner out of the way. His nerves are gone to ice and he sees the wide-eyed horror in Berik’s face and the blood bursting as the monster’s sharp sharp teeth bite deep. He grabs Reiner’s collar and runs, too panicked to think of anything else.

They run, legs burning, choking on terrified tears, and it is only once they are far away and can hear no sound of pursuit that Bertholdt wonders if they should have tried to fight, and tells himself that Berik was dead already.

Later Reiner will say that Bertholdt saved his life, too, that if Bertholdt hadn’t dragged him away he would have stayed frozen and been eaten, that running was the right choice.

Bertholdt isn’t so sure.

Bertholdt is ten and he is tall, so tall it feels like flying. He can see down onto the backs of birds, see the people crawling below like ants. Bertholdt was never a child to kick anthills for fun, but he draws back his massive, columnar leg and kicks this one, because that is what he has been told he will do, and no one ever taught him to wonder ‘what if I didn’t?’

He sees the stone fly before he hears the crack, like thunder, like gunfire, like war drums. Then he hears the screaming, sees the pinpricks of red where debris has crushed some, sees the ants scurrying in hectic panic. Then his energy is exhausted and he shrinks, venting steam, and he can’t see any more.

Bertholdt feels sick, and hopes that his imagination is making it seem worse than it is.

Reiner and Annie are waiting for him on the ground, dragging him free of his decaying body. The small monsters are gathering, like the one that ate Berik but soft-bodied and more docile in appearance — for the most part, there are a few Strangers scattered in the crowd. Bertholdt’s pulse flutters and quickens just at their nearness. He knows Annie has called them, knows this is in the plan, but he also knows Annie cannot control them and they are always hungry.

He doesn’t have much time to worry, because as soon as he is free, it is Reiner’s turn to transform. Reiner is strong and fast, and he gathers up Bertholdt and Annie in his enormous armor-plated hands, gently like handling birds, except these birds know not to be afraid. He tucks them in his mouth for safety, and they cling tight to his teeth as he lowers his head and charges.

An enormous, shuddering crash shakes Bertholdt to his bones, and he knows the second gate has broken. Wall Maria is breached.

Their mission is begun.

Bertholdt is eleven and he is surrounded by starving people and crying children and crying adults and people shouting, screaming for loved ones dead or missing, people who do none of these things because they are so badly shattered, people injured and people spattered with blood not theirs and people streaked with tears and piss and mud and puke.

Bertholdt curls up and clutches his head and screams to block out the sounds. He rocks, and sobs, unable to draw breath, because it is his fault, and his small body can only hold so much guilt. Reiner touches his back and he lashes out with a wordless screech, folding over into the mud. Annie sits motionless beside him, and offers neither comfort nor scorn.

No one else notices. Broken children are no uncommon sight these days.

Bertholdt is eleven and humanity wants to retake Maria.

He stares in shock, at first — don’t they know it’s not possible? Then he hears the whispering that crescendoes into shouting and screaming and sobbing, and he realizes that they do know. The counter-attack is a pretense. The Fall of Maria is over but a quarter of a million further lives will be lost and it is still, still their fault.

Berik’s dying face flashes into his mind. He did this, Bertholdt thinks. He has brought that terror to these people around him. He knows how it felt, he has felt it himself, and still he did this.

He sees the looks on the faces of the refugees, the shock, the grief, the helpless fear, and his own face mirrors them in dumbstruck horror. This time he does not buckle. This time he flees, and only the boy at his side sees the light fading from his eyes, his persistent fidgeting dropping away to statue stillness.

Reiner takes Bertholdt’s hand in his, warm and solid, lacing their fingers together tightly. Bertholdt does not respond. Soaring on steady vulture’s wings over a glacier-thick layer of ice between himself and his emotions, he wonders why Reiner worries. So far above everything, there is nothing to put the lie to his calm.

Bertholdt is twelve and he is in a barracks, and a boy who might otherwise have been his friend has just told him he is no better than vermin, that he and his people need to be wiped out. A boy who has just finished reassuring him of his fears, or at least the half-truths he can tell about them, can turn around so quickly and remind him that within the Walls he is a wild animal to be hunted and killed.

There are three people in the world he can trust, and one of them is dead, Bertholdt remembers.

Reiner is still talking, voice serious and sympathetic but not yet as deep as it will be. Bertholdt curls up hugging his legs against his chest with his face hidden in his knees and cannot speak, cannot do anything but retreat until the voices are just dull murmurs outside the comforting rhythmic thud of his heartbeat.

This boy who wants to kill Reiner and Annie has come to them to offer solidarity and support, because he thinks they have lived through the same thing, because he empathizes with who he thinks they are, because he thinks they share an experience. This boy who wants to kill them thinks he can be their friend, because he doesn’t know what he does not know.

Bertholdt is twelve and he is learning to fly.

He takes well to the gear, the trainees tell him, with some surprise. Shadis marks off his performance with a terse “Well done, Hoover.” Bertholdt stares after him blankly as he moves on, shocked into paralysis. Shadis slaps a pigtailed girl’s shoulders into better alignment, shouts at a wiry grey-blond boy to mind his center of gravity. Shadis does not give compliments. Bertholdt does not receive compliments. Bertholdt is not good enough to receive compliments.

He’s good at this — the thought sinks in, and he trembles, tucking his chin against his chest as a feverish warmth spreads through him. He can be good at this.

These people are all going to die, he remembers a moment later, and his heart aches. There is no future inside these Walls.

He doesn’t know why the other recruits find it hard. It feels natural, the hiss of gas, the catch and swing, the smooth parabolic curves as he arcs between points.

This is what flying feels like, he thinks. The rhythmic motion pulls him in; sink, arc, rise, the beautiful soaring moment between curves before gravity reclaims him and his hooks find another anchor to begin again. There is no room for fear, nor anxiety, nor guilt, not when all his attention is on where his anchors need to go next, on the wind whipping in his hair and jacket, on every detail his senses can relay to him. The air is cool and fresh and the sun is bright and the sky is clear and blue, the training fields at his back and the forest rich green around him, and he feels a lightness that has nothing to do with gear.

It is autumn, just a hint of bite in the air, and the woodland birds know it. They chatter in the canopy, heedless of the boy swinging through the understory beneath them, but when he whips himself upward through a gap overhead they startle, a whole flock bursting into flight.

For a moment he is surrounded by beating wings and dark bodies, a chaos of speckles and alarm calls as the starlings stream upwards. A few careless wings brush his face, his shoulders, and he is rising with them, ready to fly to wherever they go in winter, far outside the Walls, far away from everything but silence filled with birdsong and the open sky. Bertholdt laughs, the sound bursting uncontrolled from his throat. It surprises him. he’d thought he’d forgotten how.

His stomach flips in that weightless moment between flying and falling, and then he has to seek out a new anchor as he sinks. The starlings escape, wings carrying them higher than Bertholdt’s gear ever will.

Bertholdt is thirteen and Reiner is slipping. It’s subtle — shifts in his language, in the way he holds his shoulders, the way he tilts his head just so or gestures to emphasize a word. Reiner is slipping and Bertholdt is terrified; Annie has gone so cold since the Fall of Maria, and he can’t do this alone.

Reiner is scared, too, in the moments when he knows to be. Bertholdt finds him trembling and pale and tight-lipped behind the barracks, obviously just come back to himself.

“We’re not soldiers,” says Reiner, and he spits the last word with such vehemence that Bertholdt flinches. “Annie’s right. We’re not. We never will be.”

Bertholdt nods, and sits down beside him. Their shoulders brush, just barely.

Reiner is silent for a long time. Then he crumples, hunching forward and burying his face in his knees. His fingers clench in the dirt, ripping a few blades of grass up from the mostly-bald earth. “Fuck!”

Bertholdt flinches again, though he knows Reiner’s anger is self-directed.

“I can’t help it,” says Reiner thickly. “I can’t. I swore to protect you, didn’t I?”

Bertholdt’s hand finds his in the grass, gently unfolds the tight, work-roughened fingers and laces them with ones darker and longer but no less hardened.

Reiner nods. “I did. But they all think they rely on me, they all think they look up to me, and I swore — ”

Bertholdt understands. Reiner is their leader, their shield, and just by being himself he’s found himself the leader of the 104th as well. His hand tightens in Reiner’s.

“I won’t leave you,” says Reiner. “I swear. We’ll go home together, or die trying.” The phrase is all too literal, and he chokes on a dry laugh.

Bertholdt leans into him. Reiner leans back, letting his head rest on Bertholdt’s shoulder. The taller boy (when did that happen? he thinks, with a little alarm; time is getting away from him) presses his face into Reiner’s hair, closing his eyes and breathing deeply.

Reiner always keeps his word, but he isn’t always Reiner.

Bertholdt is thirteen and shivering under a too-small regulation blanket. He was never small, but he’s gotten bigger recently, and he doesn’t quite fit the standard-issue supplies anymore.

The air is dry and frigid, and his breath frosts in the air, water vapor condensing at the sudden change in temperature. His comrades (and when did he start thinking of them that way?) played at it during the day, roaring like dragons or trying to blow mock smoke rings. To Bertholdt it looked like steam, and it made him feel sick.

His back is pressed against Reiner’s side, his head resting on Reiner’s outstretched arm, but even that shared heat isn’t enough to ward off the chill. He is just drifting off despite the cold when something shifts on Reiner’s other side. He startles, twisting up on one elbow with his heart pounding.

It’s only Connie. Bertholdt relaxes, letting out a shaky breath.

“It’s r-really c-c-cold,” says Connie, teeth chattering. “C-c-c-can I — ?” Bertholdt doesn’t understand what he’s asking, until Reiner stirs with a sleepy grumble and pats the ground under his free arm. With lightning speed, as if afraid the offer will expire, the smaller boy drops to the ground and curls up against Reiner’s side.

After a moment, Connie squeaks, and there’s a rustle as he squirms closer. “Shit, man, you’re warm!”

“Reiner,” whispers Bertholdt, heart beginning to flutter again. This isn’t right. They shouldn’t get this close. It’ll only hurt the worse, when they have to turn (and when did it start to be ‘don’t get attached, you’ll only hurt them’ instead of ‘don’t get attached, you’ll fail the mission’?)

“It can’t hurt,” says Reiner, shrugging. It can, Bertholdt wants to tell him, it already has; but his eyes meet Reiner’s, green to brown squinting in the fading firelight, and he knows this is his Reiner, the Reiner who understands what he does and how much of a lie he has just told, and does it anyway, because they are thirteen and need companionship as much as any other.

It’s so close it hurts, and they can’t have it. Reiner tried, and he’s cracking, but Bertholdt can’t bring himself to take this from him. He settles back against Reiner’s side and ignores the cold dampness around his lashes when he closes his eyes.

He’s roused again only few minutes later by Sasha, who curls up catlike in the space between his knees and Reiner’s legs. Then Mikasa and Eren trail over, settling together near Connie, who has begun to shift entirely onto Reiner’s chest in his sleep. Armin follows shortly after, and apparently decides that there’s not enough room left near them, because he curls up in a ball against Bertholdt’s chest, mumbling a half-coherent apology. Jean and Marco are next, piling together next to Armin, and by this point the boundaries between individuals have totally dissolved — Connie is sprawled half on top of both of them, and Sasha is using Bertholdt’s leg as a pillow — and Bertholdt, trapped, has given up and resigned himself to a long and sleepless night. The contact makes his heart race, his palms dampen, their coolness a harsh reminder that he is not like them and they are by nature dangerous.

Somewhere along the line his body betrays him. The pile of trainees does help ward off the worst of the chill, and the combined efforts of their thin blankets make a decent covering, and he’s exhausted after a long day of hauling gear to this remote outpost, and — if he forgets the coolness, which feels like warmth compared to the open air, it’s comfortable, being together like this with comrades.

The sun is barely rising when they wake, tangled together in a nest of warmth, and Bertholdt discovers — half to his horror and half to his laughing shame — that he’s somehow wound up the focal point of a complicated knot of trainees that takes several minutes to sort out.

They’re family, but they’re the enemy. This is how Reiner snapped.

Bertholdt is fourteen and his body is changing in ways he doesn’t like. His voice shifts and cracks, breaking at the worst moments, so he tries not to speak at all if he can help it. His skin is rough with painful sores and his emotions swing more wildly even than normal, careening between shuddering rage and terrified, breathless anxiety in moments. His joints ache and he is always hungry and his shifting limbs make him clumsy, awkward, so he moves always slowly in fear of breaking something or someone with his carelessness.

This is normal, they say. It happens to children his age.

Is it? he wonders, and vaguely remembers a mention by the shadows of parents, a laugh and a promise to tell him when he was older. He wonders if they knew, then, that they were lying.

It must be normal, because he is not the only one whose voice is cracking, whose body is changing and growing in all directions. Jean’s voice has begun to skip octaves, Ymir’s shoulders are squaring and broadening, and when they all wash in a single wooden outbuilding, it’s hard not to notice other changes.

Worst of all is the height.

It seems to happen overnight: one day, he wakes up, and he is looking down onto the heads of his comrades. He’s too tall, his body stretched like taffy, and he remembers houses like pebbles and people like ants. He can’t even fly to calm himself — his new, strange shape has him crashing into branches and walls more often than not, clumsy where he never has been before, so even that’s been taken from him.

He looks down at them and thinks — he can’t. He doesn’t want to see them like that, doesn’t want to see them torn apart and devoured bloody and screaming, doesn’t want to see that ever again (he never lied to Eren, only masked the truth) but especially not to these, children like him, friends, comrades, family.

He tells himself they can’t turn back, and the fact rings hollow in his mind. There is no future in these walls, but he wants there to be.

He looks at Reiner, talking and laughing and blue under the eyes where he tries not to sleep because he doesn’t know who he’ll be when he wakes up, and thinks, That will happen to me, if I let it.

Bertholdt is fourteen and he is struggling to breathe behind the barracks, crouched on the ground with his hands over his head. He draws harsh, sobbing gasps whenever the iron in his lungs loosens enough to let him, just enough to keep him conscious, when right now he’d rather choke on his own fear.

They’d been talking and laughing and Bertholdt had even been smiling a little and then Sasha looked up at him with a pout and said “Well, we’re not all as tall as you, mister Colossal Titan,” and she didn’t know, he knew she couldn’t know, but his heart seized and his blood froze and before he was quite aware he bolted from the table.

An arm settles around his shoulders. He leans into the contact before he realizes it’s too cool, too slender to be Reiner. He sobs at the realization, because if Reiner hasn’t come for him then that means that Reiner is gone, now when Bertholdt needs him most.

“Breathe,” says the one who has come after him instead. Bertholdt does, fighting for it. The arm sinks lower, hand rubbing up and down along his spine —

Bertholdt screeches and twists away, toppling into the dust as his balance fails him. He curls up on his back, legs folded against his chest, arms thrown up defensively, and he knows how strange he must look but any attempt at pretense is drowned out by the thundering don’t touch don’t touch don’t touch; there are three people in the world whose hands are allowed near that part of him and none of them is here.

Words, that eventually fade into sense as his pounding pulse slows, as the terror releases its grip on his lungs once more. “I’m sorry. I should have asked. Are you okay?”

Bertholdt nods and collapses, slumping into the dirt. There are tears on his face, and his chest still jumps with halting, uneven breaths, but his body can’t keep tension any longer. Hands fold around his, cool and dry, fingers lacing with his own, and they tug him up to sit. He squirms, scrambling quickly to put his back against the barracks wall, and finally opens his eyes to see who has come for him.

Warm, dark eyes blink back at him worriedly. Marco tilts his head, smiling. Bertholdt closes his eyes again and kneads at his face, inhaling shakily.

“There you go,” says Marco. “I really am sorry. I should have thought. I’m sorry about — in there, too. Sasha didn’t mean it. I know that doesn’t mean a lot, but she wanted me to tell you she’s sorry, and she hopes you’re okay.”

Bertholdt nods again. Not Reiner, he thinks, and there’s a little resentment in it, because it’s their fault Reiner is slipping and their fault Marco is here in his place, but mostly he’s confused. There are two people in the world he can trust, and of them only Reiner has ever offered him comfort, but now this boy with his smile and his bright eyes and his honest concern is breaking into his world, and he doesn’t understand.

Later, Sasha perches next to him on the bunk and leans against his side and chatters, eyes shining, and after half an hour of bewildered one- and two-word answers, Bertholdt realizes this is her way of apologizing.

She should hate him, but she doesn’t. Bertholdt keeps cleaning his gear, hands moving mechanically, letting his shell of a face hide the thoughts circling in his head. None of them do. They don’t know any better.

Bertholdt is fifteen. Tomorrow, he and Reiner and Annie will be gone to the Interior.

The day is cool, but he feels feverish. His palms are slick, his hands trembling, and his hair straggles damp against his forehead. His heart is pounding, his mouth dry, and he wants nothing more than to wedge himself into some secluded crack in the Wall until he joins his ancestors as part of the masonry.

Earlier, Eren asked if he was okay. “Nerves,” Bertholdt had said, and then, “Relief,” and then, realizing how paradoxical he sounded, “Um — ”

Eren nodded and smiled and slapped his arm (not quite able to reach his shoulder), used by now to Bertholdt’s stuttering inarticulacy. “You’re fine,” he said. “You made it, right? You’ll go to the Military Police like you wanted. You’ll never even have to hear a Titan again.”

Bertholdt nodded, rubbed his arm where Eren had hit him, and forced a weak smile, trying not to be sick as he remembered what he would do in a few hours to his friend who had already survived the loss of one Wall.

Now he looks down off the Wall at the forest below, deceptively innocent and free of Titans, and swallows. The Garrison are for the most part down below, and the recruits are gathered further along the curve of Trost’s outer gate. No one is watching. No one will see.

He steps back and runs, long legs gathering speed quickly. Then his foot hits the edge of the Wall, his knee bends, and he launches into a flying leap into the sky beyond Rose.

For a moment, he closes his eyes and lets himself enjoy the freefall. The wind whips at his hair, dragging his jacket up behind him like wings, and he is weightless, free, soaring. Then, before carelessness can shatter him against the ground, he puts his hand between his teeth.

He doesn’t think it feels like flying, this time. He knows better.