Eren woke for the third time that night to the sound of somebody shifting, tossing and turning on their straw-filled sleeping mat. Blinking tiredly at the ceiling of the abandoned stable they'd taken refuge in, Eren rubbed his sore eyes, wondering who the hell was making that noise.

Buuuuuuuuuuuuurp.

Startled, Eren pushed himself up on his elbows and glanced around, but he couldn't see in the dark.

"Mikasa? Geez, was that you? Keep it down, the titans'll hear us."

"No. It wasn't me." There was the sound of someone stirring from Eren's left. "Armin?"

Silence. But, there were only the three of them there.

Mikasa struck a match, and it flared to life, illuminating the three figures in their sleepclothes. Both Eren and Mikasa noticed that Armin was sitting curled up with his head down on his knees, trembling.

"S-sorry." Even the smaller boy's voice quavered. "I—hic—didn't want to wake you two up. M-my stomach is hurting pretty bad, though." As soon as he stopped speaking, Armin's hand flew up to cover his mouth, but he was unable to stifle another surprisingly loud belch.

"Aw man, I bet that cheese we found in here went bad." Fighting a yawn, Eren scooted closer to his friend on his hands and knees and sat beside him, rubbing his back. "Bet that's why you're sick."

"You and I ate the cheese too, Eren." Mikasa moved nearer to Armin too, setting the lantern down by his side. "It didn't make either of us sick."

Mikasa sat in a crouch and stared. Armin couldn't help but lift his head to meet her eyes, though his face was red with embarrassment, nose scrunched up with discomfort.

"What are your symptoms, Armin?"

"Uh." Armin swayed back and forth, cringing as his stomach rumbled audibly. "It feels like there's a lot of pressure in my stomach and chest. I keep burping, and it feels better for a minute, but then I just start feeling really sick again."

"Have you eaten cheese or dairy products before?" Armin shook his head, hand going over his mouth again to muffle a small, strained burp. Mikasa nodded, thoughtful. "You probably have a milk allergy."

"Wha?" Eren's hand paused on Armin's back. "Wait. People can be allergic to milk?"

Ignoring Eren, Mikasa gave a curt nod and stood, walked to the side, and began rummaging through their field supplies. She took some kind of white powder from the medical kit, poured a bit into a water flask. Returning, Mikasa gave the contents of the flask a good shake before handing it to Armin.

"This is just water and baking soda. It isn't much, but if you drink it all in one gulp, it should help relieve the pressure."

Armin took the flask from Mikasa with a trembling hand. "Th-thank you." Squeezing his eyes shut, tears budding at the corners, Armin downed the contents of the flask in a single swallow, then drew in a sharp breath, grimacing at the salty taste. "I'm sorry to always be so much trouble."

"Don't apologize for being sick, Armin." Eren gave his friend an encouraging thump on the back, turning to look at Mikasa. "How did you know about the baking soda?"

"I knew it. You didn't read the medical guide like you were supposed to." Having put the last of the supplies away, Mikasa returned to the boys and sat on Armin's other side, reaching up an arm to rub his back along with Eren. "Don't worry, Armin. Eren and I will stay up with you until you start to feel better. Right, Eren?"

Eren jerked upright, frowning. "Of course! You don't have to tell me that."

Bowing his head, Armin laughed weakly, fighting off a groan. "Thanks, you guys. I'm starting to feel better already."