It started with Eren.

It was one of those nights where no matter what he did, he couldn't deter the chill of the castle dungeon. Not with his abnormally high body temperature, not with the large blanket Hange had supplied for him last month. Lying in his bed, his mind wouldn't let him sleep until he warmed up, so Eren left.

A little while ago, the door to his dungeon had stopped being locked every night. It was something that if the Military Police heard of, there was sure to be hell to pay, but the Survey Corps were lax. Eren had been with them long enough now that it was pretty clear he wasn't going to turn into a titan overnight and eat everyone.

Eren had memorised his way out of the basement well enough to maneuver in the dark. When he made it up the staircase, the air was warm with the arrival of spring.

He wandered the halls for a good hour before finding the door to the roof. And when he did, he stayed up there all night long.

This went on for a fortnight, with nobody noticing. Eren would wait until everybody upstairs was asleep, leave his bed and climb to the roof. Most nights it was windy, but the warmth that had chased winter away made it bearable to stay. Sometimes, on cold nights, Eren would bring Hange's blanket with him, and walk the halls cocooned in the thing until he reached the roof. Then, he would lay on it, staring up at the sky. He could do it for hours, whether it was cloudy, hazy, or better yet, clear. Time passed differently when Eren was atop the castle, but he always made sure to scramble back to the dungeon before morning came to squeeze in some sleep.

"You look tired, Eren," Armin stated at breakfast one morning. He was absolutely right- cutting back on sleep fashioned weary eyes on Eren's face, but he usually snapped out of his lethargy by mid-morning when training rolled around. That was all that mattered, really. If Eren could perform well as a soldier, and get to visit the roof every night, he was happy.

Armin was one to dig deeper into situations he didn't understand, and as many times as that skill had saved Eren, he detested it when one night, Armin followed him to the door.

"You weren't sleeping," Armin said. "I wanted to know why."

Armin always wanted to know why. His deepest instinct was to understand how the world worked.

"Promise you won't tell," was Eren's only request. Armin wouldn't tell. Not for the sake of knowledge.

It was a clear night. Eren showed Armin the stars.

The second night was just as clear, and both boys automatically met each other at the door. Eren had his blanket, and this time Armin had something in his hands.

"I brought a notebook," he said, eyes jubilant and grinning ear to ear. "We can write them down."

Eren laid out his blanket for the two of them to lay on. It was big enough that they were opposite each other, heads side by side.

"My grandfather told me that people used to draw shapes in the sky," Armin told Eren. "Then they'd give them stories."

Eren hummed. "That one looks like a smiley face."

"That's too easy," Armin chastised, but drew it in his notebook anyway. He named it, The Smiley Face.

They'd work on the naming process later.

"Look at that one," said Armin, pointing to a W shape in the sky. "It looks like an ocean wave."

Armin promptly drew it in his notebook.

Eren looked at the wave in the sky. "Why don't you name it?"

"I did," Armin said. "It's the Ocean Wave."

Eren pointed up. "There's five stars up there. There's five letters in ocean. What if that one was O, that one was C, and so on?"

Armin stared at his notebook. Then, he labelled each star a letter of the word ocean.

"Here's the story," Armin began. "It was a really windy day, and the waves were so high that one of them hit the sky. Then it got stuck there."

"That could never happen," Eren replied. "It's impossible."

Armin shrugged. "It's the story."

The next few nights didn't last as long. It was cold out, but Eren was a pretty good source of body heat. Some nights, they'd lay on the blankets, others, it would be hung from each of their shoulders to deter the breeze. Armin's notebook was finally receiving some use.

It was all the same to Armin, who sometimes ended the night early, if only to make Eren get more sleep.

Apparently, it wasn't enough, because the pair was eventually confronted by Mikasa.

"You both look exhausted," she observed, a little after a week.

Eren looked at Armin.

Armin looked at Eren.

Eren nodded.

"You can't tell," Armin said to Mikasa, revealing the only condition of their clandestine nights. Mikasa pulled her scarf over her mouth, and nodded.

That night, it was clear. Mikasa joined Eren and Armin on the roof. There was plenty of room on the blanket, and now their heads were touching, in a triangle.

"That star is the brightest," Mikasa declared. "Let's name it Eren."

Armin wrote it in his notebook, wondering how he never thought of that in the first place.

They hadn't meant to stay out all night long, but Armin moved next to Eren for warmth, and Mikasa wrapped her hands in her scarf. One by one, their eyes closed, and opened to rays of sunlight.

Mikasa was the first up, and she lightly kicked Eren's side that wasn't covered by a dozing Armin.

Neither boy woke up until the sound of the door swinging open sounded throughout the roof. In a sleep-induced haze, Eren awoke to the abrupt bang of wood against stone, and blinked several times before letting Armin fall as he sat upright after recognising the figure in the doorway. "Captain Levi! Sir!"

Eren's salute managed to wake up Armin as Levi stepped forward.

"You brats," Levi droned. "You incompetent shits. Eren, your absence has had Erwin losing his head downstairs for fifteen minutes, you know."

Eren's fist shook against his chest. "My apologies, sir!"

Levi circled the blanket. "What, did you decide to go camping? Aren't you familiar with what happens if we break your supervision court order?"

Eren shook his head. "I get handed back to the Military Police, sir."

Levi looked down at Eren. "And I'd likely be court-marshalled. Then humanity is utterly fucked. Why, in the name of Sina, are you on the roof?"

Eren was speechless, but Armin came to his aid, holding up his little brown notebook. "We sometimes look at the stars, sir, because Eren can't sleep."

Levi supplied a look of disbelief, before pointing lazily at the door. In a flurry of footsteps and a flailing blanket, the trio was out the door, and racing to start their day.

Levi looked at the cloudless sky. So the brat couldn't sleep, huh?

The next night, Levi stood outside Eren's dungeon door before the boy had gone to bed. Eren couldn't help but look at his superior apprehensively. Was he here to reprimand Eren? Was he going to start locking the door again?

"You look like you're holding in a shit," Levi deadpanned. "Are you going to shit, or are you going to follow me?"

Eren blinked, confused. "Follow you, sir?"

Levi jerked his head down the corridor. "Bring that filthy blanket with you, brat."

Baffled, Eren wore his blanket like a snail a shell as he followed his Captain up the stairs. They walked into the kitchen, where Mikasa and Armin sat patiently waiting. Armin was holding his notebook tight.

"Uh, Captain, sir?" Eren asked. "What are we doing?"

Levi poured a kettle full of water into a teacup. "Making tea," he supplied. "I'm not bringing you shits to the rooftop without a cup."

Eren's eyes widened as he looked to Armin, whose face was alight with joy. Levi took his tea and led the three of them to the top of the castle, where the sky was exceptionally clear, and the air was warm. Tonight, the blanket served as simply a cozy cushion to protect them from the stone.

Eren, Armin and Mikasa named the stars, while against the wall, Levi sipped his tea.

One week and four stargazing nights later, Armin struggled to pull his book from Jean's grasp.

"Now, hold on," Jean protested. "I just wanna look at it."

Armin circled Jean, who kept his back to the blonde as he flipped through the pages. "Be careful with it!"

Jean looked at dots connected by lines, and the labels that decorated each drawing. "What are you? An author?"

"Those are diagrams," Armin said, reaching under Jean's armpit and effectively stealing his book back. He returned it to his box of belongings under his bunk.

"I wasn't making fun of it," Jean defended. "What are they for?"

Armin stared petulantly at Jean. Should he really tell him about the secret? Eren might not like it, but Jean wanted to know. They already weren't alone anymore since Captain Levi had started supervising them. Armin would just sit in between Jean and Eren to keep them apart.

Apologising to Eren in the back of his mind, Armin told Jean about the roof.

"It's a secret," Armin said, keeping his voice low as he watched Connie walk into the room accompanied by Reiner. "You can't tell anybody. Only Eren and Mikasa will be there."

Jean frowned at that, but he still walked with Armin that night to meet everybody at the door.

"Armin," Eren groaned once his eyes fell upon Jean. "Did you really have to?"

Armin glanced from a disapproving Eren to an equally pissed-off Jean. Yes, he did have to. It would be fine when they were separated on the blanket. They'd be too busy looking at the stars to argue.

Levi arrived at the door last, holding a steaming cup of tea. "If you brats start bickering, you're all sleeping in the dungeons."

The threat chilled the spine of even Eren, who did not look forward to sleeping on the same floor as Jean. "Yessir."

Eren was on the edge of the blanket, with the extra fabric curled over his body. Armin had his notebook and was next to Eren, followed by Mikasa, and then Jean. Levi remained perched by the door.

"That one," Jean said, pointing to a collection of stars beside the one Mikasa had deemed "Eren". Jean elbowed Mikasa in the side. "It almost looks like a proposal, right? With someone sitting down and someone standing up."

"I disagree," Eren mused. "That's definitely a horse. Kind of reminds me of you, Jean."

"You fucker," Jean growled.

Eren would have sat up in anger if it weren't for Armin gently pressing his hand on his best friend's chest. "At least I'm not a horse fucker."

"Oi." Levi's voice drifted from the far wall.

Armin smiled as he wrote Horseface as the title of Jean's constellation.

As luck would have it, the next three days were nothing but rain. It was common knowledge in the barracks now that Armin and Mikasa left some nights, and that Jean had recently begun tagging along. So, no one questioned Armin when he slipped out of his bed each of these nights and went to join Eren in the dungeon.

It was cold down there still, even as they were well into spring. Eren always shared his blanket. A cracked old lantern sat in the corner of the dungeon, and it was just tall enough that if Armin and Eren sat across from each other on Eren's bed, they could drape the blanket on top and let it fall around their heads like a tent. From here, Armin would open his notebook, and they would dream.

"I don't get it," Jean said, the next time Armin opened his notebook. The four with the secret were sprawled out on the field outside on the next sunny day. On one page was a scribble of a flower, with each star named after plants in Eren's mother's garden. On the opposite page was the constellation labelled Horseface. "Why does the horse have a thing on its head?"

Armin shrugged. "We didn't really know what to do with the extra star at the top, so we added a horn."

Jean shook his head. "That's impossible. It could never happen. Now it's not a horse."

"It's the story," Eren protested. "It can be whatever we want."

Jean leaned back. "I still think it's stupid. If you keep adding random shit, nothing'll make sense."

Armin smiled as footsteps sounded behind the group in the grass. "It doesn't have to make sense, Jean. It's in the sky. Eren, what if we gave it wings? What if it could fly?"

Eren leaned over Armin's shoulder and peered into the notebook. "That's doing Jean too nice. We could probably find another horse in the sky. That one will have wings."

"Thanks for never listening," Jean muttered as a shadow loomed over the four recruits.

"Hello, hello," Hange said, hands on her hips and smiling at the group below on the grass. "Levi and I are heading inside, Eren, so now would be a good time to come in and finish chores… what have you got there?"

Armin and Eren exchanged a glance, before Eren nodded. Armin gave Hange the secret.

To what was likely Levi's dismay, Hange sat down on the grass between Mikasa and Armin, so that she could flip through the book. "This!" she whooped, flipping through all the drawings. "This is fantastic! And you all work on this, every night?"

"When it's clear," Eren clarified. "We can't really go out when it's cloudy."

Hange looked up at the sky. Other than a puff of white near the trees, the sky was nothing but blue.

"You've got a great start to these charts," Hange exclaimed. "Might I recommend writing down the date and time, since the sky is always moving."

Eren's eyes widened. "Moving?"

Hange nodded. "Moving. Because of our location and the way our planet spins, the stars in the sky change in the winter and summer. We can see different planets, too. You know, I went through an astronomy phase a couple years ago. I could tag along with you some nights and oh, I don't know, keep Levi busy!"

"It's clear tonight," Mikasa commented. "Come. They never taught astronomy in Shiganshina."

As Hange sat and discussed the evening with the recruits, Levi peered out his office window at the field and sighed. A Hange-level science talk appeared to be commencing. If one thing was for sure, Eren wouldn't be cleaning anytime soon.

Eren, Armin, Mikasa and Jean was the regular line up on Eren's giant blanket. Hange sat with her back against the wall Levi leaned upon, sipping away at his tea. She grinned. "You told me to throw out that blanket, Levi. Who's laughing now?"

"Still me," Levi deadpanned. "It's a mangy old thing I wouldn't give a homeless sap."

"It's being put to great use!" Hange corrected. "You're mad it wouldn't fit over your bed, hm?"

Levi scoffed. "Like I would let that lump of filth ten metres near my bed, four eyes."

Jean raised his arm to the sky. "Those two next to the horse," he said.

"Next to the what?" Eren questioned.

Jean scowled. "Next to the horse. With the horn."

Eren raised a brow. "The what with the what?"

Jean threw his arms up in a burst of rage. "Horseface! Next to Horseface. Those two bright stars. I want to name it."

Muttering to each other fondly, Eren helped Armin spot the two stars Jean was talking about. Armin flipped to a new page, even for a drawing so diminutive. "What do you want to name them?"

"The dim one Jean," Jean said, and Eren snorted as Armin wordlessly fulfilled his request. "And that bright one, Marco."

Eren quieted as Armin finished writing the labels, and documented the date and time.

Bumping into Sasha and Connie was a total accident.

"My bread!" Sasha yelped as Jean stumbled back from their collision. Both groups had been rounding the corner, with Jean, Mikasa, Armin and Eren all on their way to the roof. Sasha and Connie, it seemed, were returning from the kitchen.

"What are you even doing up?" Eren questioned. "Isn't the kitchen locked at night?"

Sasha picked up her bread and nodded, taking a bite. "We have our ways."

Mikasa made a face. "That was on the floor."

"Wait, wait," Connie said, following the four as they continued on their way. "What are you doing up? Is this that thing, where you always go sneaking off?"

"Can we come?" Sasha asked, excited and with a mouth full of bread.

Jean exited the conversation, knowing the question was above him. He and Mikasa both looked pointedly at Eren and Armin.

"It's a secret," Eren finally said. "You can't tell anyone."

Connie gave a mock salute while Sasha devoured the rest of her bread. "Mph! You can trust us, Eren!"

Connie whacked Sasha. "Keep your voice down. It's a secret, remember?"

Levi and Hange were already waiting on the rooftop when the six recruits shuffled through the door, and Eren draped his blanket on the ground. Neither were surprised by the growing number of soldiers joining them, but it was getting to be a bit ridiculous.

"A secret," Hange hummed. "Soon the whole castle will be up here."

There was just enough room on the blanket for everybody to lay facing up at the sky. The stars were brighter tonight, as if excited they got to show off to more people.

"I never really realised how many there are," Connie commented. "What's that bright one?"

Armin looked to where Connie was pointing, at a star sparkling just above the treeline. "We don't know yet," he offered. "Want to name it?"

"Ragako," Connie said immediately. "Check it out. The ones around it kind of look like a house."

Armin thoughtfully dotted down the collection of stars, naming the shiniest Ragako. "Isn't that the name of your village?"

"It sure is," Connie replied. "See how it flickers? Jeez. I can't wait to go back and tell everyone I'm in the Survey Corps."

Hange cleared her throat. "It sparkles because of the refracting light!"

Levi sipped his tea. "No one cares, four-eyes."

Connie sat up. "Actually, that's interesting."

Hange clapped her hands together. "Oi, Connie! You should come by my office sometime; I can tell you more about it!"

Connie slowly laid back down.

"I understand how you see a house, Connie," Sasha began. "But I see an apple."

Connie sighed. "Of course you do. Look to the left, idiot. That one's an apple."

Armin's notebook was almost full.

"Not like that," Sasha said, taking Armin's pencil and redrawing the constellation. "Its legs are a bit to the side. The top is the head."

Armin unwillingly tried to follow along with Sasha's ramblings.

"Face it, Sasha," Jean said. "No one else is seeing it. You're crazy."

Sasha's mouth dropped open. "I'm not! You can see the arms, and the legs, and the five on the side make a bow! He's even wearing a belt. That's clearly a hunter!"

The rest of the group was silent.

Flopping back down onto the blanket, Sasha groaned. "How can none of you see it?"

Eren shrugged. "I see the belt."

Armin dropped the notebook into Sasha's lap. "I think you should draw it instead."

Even after a few weeks, the secret remained a secret. Hange had the bright idea of bringing up a bench from the meeting room for her and Levi to sit on. Erwin had been perplexed all the next day as to its whereabouts, and now, Levi sat on the edge, with Hange's head in his lap and her legs dangling over the armrest. It provided a good view of the sky.

Levi sipped his tea. "Do you really need to rub your greasy hair all over my pants?"

"You know what," Hange said, changing the topic and loud enough for everybody to hear. "I don't think Levi has named anything yet."

Eren pointed sideways. "Those ones kind of look like a teacup."

Armin scribbled in his notebook.

Resting the teacup on Hange's forehead, Levi reluctantly looked at the sky. Out of all the times he's been supervising the younger soldiers and Eren, he never actually focused on scrutinizing the stars. He would simply watch the recruits create their own world from the wall.

Levi pointed lazily at one wide cluster of stars. "Is that spot taken?"

Armin flipped through his notebook. "Next to the Hunter? Not yet, sir. And I still have a page left."

Levi observed the stars. Two bright ones forked off into two, making a tree-shaped impression on the man.

"I suppose if you look sideways, it can be seen as a tree," Levi pondered. "It's short and wide. A Magnolia Tree would do."

Hange could feel the teacup wobble on her head, but Levi's grip was firm.

Armin completed the documentation in a flash. "What's the story behind that, sir?"

Levi was silent a moment, and lied. "I don't know. Make something up."

"The Hunter!" Sasha began. "The Hunter was travelling for days."

"On his stupid, horny horse," Jean added.

"His house was all the way across the sky," Connie continued. "The journey took forever."

"He fed his horse an apple," Mikasa mused. "One as red as my scarf."

Armin whispered something into Eren's ear, and closed the notebook. The sky was now complete.

"He was tired, so he sat under the Magnolia Tree," Eren finished. "And he stared out at the ocean. He's free."

Levi sipped his tea, his voice quiet. "You brats and your imaginations."

From Levi's lap, Hange could see a shine in Levi's eyes that wasn't there before, and had the audacity to grin while keeping her voice to a whisper. "Touching, isn't it?"

Levi placed the mug back on his friend's face. "It's the fucking light refracting, idiot. Get your glasses checked."

On the blanket, and despite the warming temperature, Armin snuggled closer to Eren. "I'm out of pages," he remarked.

"We'll find a new one," Eren reassured his best friend, who kept a tight grip on his decrepit notebook. "There's still stories to tell."

Every night, the sky changed just a bit, and every night, the secret-keepers got to name new stars and create their legends. There were endless stars to name, and it was impossible to find them all, but that didn't stop them from trying, no matter where they were.

Some guides to which constellations and stars are which, if you're interested:

Constellations:

The Smiley Face- the Northern Crown

The Ocean Wave- Cassiopeia

Horseface- Unicorn

The Other Horse- Pegasus

The House- Cepheus

Apple- Taurus

The Hunter- Orion

The Magnolia Tree- Cancer

Stars:

Eren- Sirius (Canis Major)

Jean- Gomeisa (Canis Minor)

Marco- Procyon (Canis Minor)

Ragako- Capella (Cepheus)

P.S. Magnolia trees aren't currently native to Europe, but they were 100 million years ago according to fossil records so there