An accident in Hange's laboratory turns Armin into a six year old, physically and mentally. Confused and fighting to adjust, will the Survey Corps find a way to change Armin back, or will they lose their strategist forever?

Just a little something I'm writing to get me back into the writing mood. Set sometime in the period between the cadets joining the Scout Regiment and the 57th Expedition, which I decided to make longer than a month for my own twisted purposes.

Disclaimer: I do not own Attack on Titan (Shingeki no Kyojin) or anything else.

Levi decided that there was no possible way for his day to get any worse.

The nightmare had begun earlier than usual, as, just before dawn, the Jaeger brat had decided to transform into a Titan in his sleep, which just about destroyed half of the castle that they were using as a base. Jaeger was also apparently unaware that he was awake, and proceeded to run around destroying things until Arlert got him to calm down.

Then, of course, Jaeger was so fiercely apologetic and Arlert defended him so well and Ackerman so determinedly refused to let anyone near him that Erwin let him off without punishment. And Levi was left to supervise the cleanup of Jaeger's mess.

Once they managed to clean the place up, after heavy incompetence on the part of the new recruits and numerous death threats from Levi, there was hardly any time for training, which everyone complained about, and he caught the Braus brat with stolen food again.

Then, Kirschtein and Jaeger got into an argument at dinner over who knows what and Levi had to physically rip them apart, which earned him a glare from Ackerman. Afterwards, Erwin announced plans for another expedition outside Wall Rose, which Arlert was supposed to go over with him. So, if anyone saw Alert, he was supposed to report to Commander Erwin as soon as possible. Levi was ready to lock himself in his room for the rest of the night and let the brats sort things out for themselves.

And so, just as everything was supposed to be settling down, there came the sounds of an explosion from Hange's lab.

No, the day could not possibly get worse.

Levi told everyone gathered around the entrance to the lab to step back before he pounded on the door.

"Hey! Shitty glasses! Open up! What are you up to this time? We've already had half the base blown off today!"

The door suddenly flew open just far enough for Hange's head to emerge. She peered around at everyone suspiciously before catching sight of Levi.

"Oh! Hello, Levi. I thought I heard you calling. What brings you all down here, huh?" Hange spoke rapidly, the usual grin on her face and excitement in her voice.

"We're here because you shook the entire castle, shitty glasses. Care to tell us why?" Levi put a hand on the door, prepared to force his way inside.

Hange tried to close the door. "Oh, nothing. Just my usual projects, nothing new in here, thank you, goodbye!"

"Can I talk to Armin, then?" Jaeger piped up, joining Levi in his attempts to get past Hange.

"Armin? No, he's not here right now. Why don't you go look for him somewhere else?"

"No!" Eren yelled, "I know he's in there! He took over for Moblit so he could get something to eat and he didn't come back! What have you done to him?!"

Hange decided to put more effort into closing the door than providing an answer, but the rest of the recruits chose that moment to help force the door open. Hange jumped back as everyone tumbled into the room.

The lab was in complete disarray. There was shattered glass on the floor, papers scattered everywhere, and a heavy mist in the air. Arlert was nowhere to be seen.

"See?" Hange said, gesturing to the mess with both arms and blocking the way into the aisles. "No Armin here, just a mess. Nothing to worry about. You should all just go and look for him elsewhere, and send Moblit to me if you find him."

"Then why don't you stop blocking the way and let us see what you're hiding down that aisle?" Mikasa Ackerman remarked, her voice low and cold.

Hange giggled nervously. "That's really not necessary."

Jaeger suddenly caught on. "What did you do to him?" He tried to rush forward, but Ackerman and Kirschtein held him back. Levi, on the other hand, proceeded to calmly walk around Hange and turn an apathetic glare between the long tables.

And he froze.

He just had to let himself think the day was over, didn't he?

"Hange," Levi drawled, for once struggling to remain calm. "What am I looking at here?"

Hange sighed and gave up trying to block the way. "I'm honestly not sure. I was trying to make a potion that would make Titans smaller, but Armin tripped on something and we sort of… accidently knocked a few beakers into each other. It really made a mess, huh?"

Jaeger broke free and rushed past Hange and down the aisle with a startled cry, Ackerman right behind him, to the tiny body on the floor.

Jaeger knelt next to the small form and gently rolled it over, finding himself staring at the unconscious, disheveled, much younger form of…

"Armin?!"