A/N: This story is a collab with the-clarity-organism

Sonic's house was a puny thing, embarrassingly weak in its simple construction and modest size. Why would Sonic live in such a place? Metal had no idea. He was used to the grand, sweeping structures the doctor erected to illustrate his superiority.

But Sonic? What he lived in could barely be considered a house. Tucked away on the far end of town, the simple building stood hidden behind a row of scraggly trees. The trees were home to many animals, and they chirped annoyingly at Metal as he walked up to the door.

Metal shooed them away with the back of his hand then raised his fist.

He knocked.

There was a silence at first, a long, drawn-out silence that Metal knew Sonic would normally never tolerate.

Then there was the sound of movement from the other side of the door. The doorknob clicked. The door opened.

Sonic stood in the doorway, leaning against the frame. His posture was lax, his eyelids were drooping, and he had a blanket draped around his shoulders.

"Heeey," he greeted, though it was almost slurred. "Whatcha doin' here, Metal Sonic?"

"What am I doing here? That question is incorrect." Metal folded his arms, sharpening his gaze. "The real query is: what are you doing here?"

"Uh—" Sonic slumped further down the doorframe, looking confused. "This is my house."

"Exactly!" Metal threw his hands up. "And where are you supposed to be right now?"

Sonic blinked. He was silent for another painfully long time.

One of his ears perked. "O-oh...oh!"

He shook his head then covered his mouth with his hand. He made a strained sound that Metal didn't recognize.

"W-we were gonna fight, right? Sorry, but—uh—we're gonna have to rain check that." His cheeks reddened as he pulled the blanket further over his shoulders. "I'm not feelin' too hot."

Nothing about Sonic's statement added up, and it took Metal a moment of standing there, optics flickering, before he ran out of branches on his decision tree. "Is your internal thermostat no longer regulating homeostasis? Is that why are you are insulating yourself in this giant cloth?"

"My internal... what?" Sonic groaned, rubbing the side of his head. He looked around then gestured for Metal to follow him inside. He walked over to the couch then collapsed onto it. His face eased with relief. "No, I'm sick."

Metal trailed behind Sonic and into the house. The interior was much like the exterior: simple and efficient, no more and no less than what it needed to be.

Metal asked, "What does that mean?"

Sonic peeked up at Metal, an arm lazily draping off the front of the couch.

"It means I can't really think straight or fight right now." He managed a small smirk. "Otherwise I could totally kick you around like you want."

Metal considered this, crunching the carpet beneath his metallic feet as he paced. Sonic was refusing to fight him. Metal needed to fight him. This was a blocker to his goal.

But why couldn't Sonic fight him? Metal had precious few facts. Sonic's homeostasis was malfunctioning, so Sonic had to procure extra insulation. Sonic also said he couldn't think straight. Was something corrupting his internal data stores? Combined with the homeostasis malfunction, that would mean—

Metal's optics widened. "You are infected!"

"...Infected?" Sonic pressed the side of his head into the couch's pillow. "That's one way to put it, I guess."

Metal immediately flipped off his network switch. If Sonic had a worm, Metal was absolutely not going to get it. He still remembered the last time something got past his firewall. Dr. Eggman had not been pleased, and the mere memory of it got a shiver from Metal.

But he couldn't just leave. If he were to complete his goal of fighting Sonic, he had to remedy this.

"What firmware version are you running? You should update your drivers will every release, Sonic. Anything less is negligent. That is likely how you got this malware."

Sonic tilted his head, raising a brow. He flinched then covered his mouth and let out another loud noise into the palm of his hand.

"That's a computer thing, right?" he asked. "This isn't like that."

Metal cocked his head in confusion. "Not your firmware? Is it your network driver then? What port number do you run your protocols on? You should be denying anything other than 443."

"Er..." Sonic's head plopped back onto the pillow. "Sorry, y'lost me."

Metal let out a frustrated beep, pinching the bridge of his optical screen. "Then can you not tell me what you are infected with?"

Sonic shrugged. "Pretty sure it's just a cold."

"A cold? That identifier does not match any know computer virus. Is this a slang term?"

"A computer..." Sonic trailed off. Then he let out a weak chuckle. "Wait, you think I'm a computer?"

"What? No, do not be ridiculous." Whatever Sonic had, Metal was protected from it with his network off, so he scooted over and sat down on the couch across from Sonic. "You are clearly mobile, and computers are not. That makes you a robot."

Sonic snorted. "Okay, I get it now. 'Least this means I'm not as sick as I thought with how badly I was understanding you."

He smiled cooly, eyes half-lidded as he stared at Metal. "I'm not a robot."

Metal's optics flickered for a brief second. He had never been so close to Sonic before, at least when they weren't fighting, and Sonic had never looked at him this way.

This virus must be really serious.

"If you are not a computer and you are not a robot, what in the world are you?"

"Egghead really doesn't let you get out much, huh?" Sonic eyed a wet rag on the table, then gestured to it, as if to ask Metal to hand it to him. "I'm a mobian. Don't you know what that is?"

Metal scooped up the rag with the back of his fingers and let it flop onto Sonic's lap. "A mobian? No, what is this?"

Sonic took the rag and laid it down on his forehead. "Uh...well, it's not a computer, for one thing? Or a machine at all, really. It's a living thing."

"A living thing?" Metal cocked his head in confusion. "Such as a plant? Or—"

Technically, Metal had a way to answer this. He could look it up through his online database. That required turning his radio back online, but maybe that was safe. Whatever Sonic had, Sonic seemed convinced it wouldn't affect Metal.

So he clicked on his radio, emitting a faint, electric hum as he looked up the answer.

Then his optics widened. "Oh. I see. I had no idea but—this does seem wholly different."

Sonic attempted to whistle, but his cold seemed to be affecting his sinuses. So he just pretended like he had successfully done it anyway. "Life as Eggman's robot must really be bad if he doesn't even let you in on stuff like that."

Metal's optics widened as he processed the data further. "Sonic! You did not tell me biological viruses were so horrible! They—they—"

Metal lurched toward Sonic, grabbing his shoulder with a look of sheer and utter horror. "They are inside your cells."

"Uh..." Sonic glanced off to the side. "Yeah? It gets better though."

"'Gets better?'" Metal grabbed Sonic's other shoulder now, pulling him even closer. "Those viruses are causing your cells to explode."

The pull seemed to have made Sonic slightly dizzy. He shook his head and made another sound—Metal now knew it was called a cough—off to the side.

"It's not as bad as it sounds. I'm not dying or anything, Mets." He snorted. "That's your job after all, right?"

Metal placed his palm against Sonic's head, holding him carefully. "That is right! And I cannot allow some kind of protein-encased, ribonucleic death acid to do my job!"

Sonic flushed at the touch to his head. It was probably just his fever.

"You're determined. I'll give you that," Sonic chuckled.

"That is correct. I will not let anything stand in the way of priority one hedgehog."

Metal didn't move. "Ah, so then...how do I repair you?"

"Wait—" Sonic blinked. "You're serious?"

"Of course I am serious. To defeat you would mean nothing unless you are operating at full capacity. So how do I repair you?"

Sonic paused for a long time; so long that Metal wondered if Sonic's illness had somehow prevented Sonic from hearing him.

Finally Sonic shrugged, an amused smile on his face. "Getting rid of a cold takes time, Metal. It's not like a repair where it gets fixed as fast as you can move."

"...I see." Metal pulled back, now sitting next to Sonic on the couch. "So there is nothing I can do to aid your recovery?"

"Not exactly." Sonic took a moment to bury himself back in his blanket. "I mean, sleep is all on me, but I also need good food and medicine."

Metal studied Sonic for a moment, his processors whirling.

Then he sat up. "That decides it. I will stay here with you until you recover."

Sonic stared at Metal, still looking at him with a mixture of disbelief and amusement. He laughed. "You're crazy."

He rolled onto his other side as if trying to get comfortable. Suddenly, he shivered.

Metal slid off the couch, taking a step toward Sonic. He again placed his hand on Sonic's cheek. "Sonic? Are you cold? You are shivering."

Sonic peeked back at Metal. "Heh, that's another mobian thing."

Metal considered this. From his recently gathered data, he had come to realize that mobians require energy to stay warm. If Sonic was shivering, he would run out of energy. Then the cold virus would get the better of him, and Sonic would get even sicker.

Metal could not allow that.

"Unacceptable," Metal said. And before Sonic had time to react, Metal had slid his arms beneath Sonic. With a single motion, he then flopped down onto the couch and pulled Sonic into his chest. "You must recover."

Sonic let out a small yelp, placing one of his hands against Metal's chest. His muzzle was turning redder yet again.

"Um—" He glanced up at Metal, seeming at a loss for words. He looked away. "...thanks."

Metal nodded with satisfaction. His plan was a success.

"There is no need to thank me. This is all merely for your future defeat by my hand."

He pulled Sonic closer.

Sonic nodded in return, though hesitantly. "R-right."

He stared at Metal's chest for a long time, his hand still against it. Slowly, he leaned towards Metal, almost nuzzling Metal's shoulder as he absorbed the warmth.

Metal wrapped his arms around Sonic's back, leveling Sonic's weight against him. Shivering he may be, Sonic was also incredibly warm, and this fact surprised Metal.

Nonetheless, he stayed steady, letting Sonic fall into the most comfortable position.

Sonic looked around, almost seeming to be embarrassed by the fact Metal was holding him. Which was ridiculous, given that Metal was doing the most optimal job at this task.

Metal's optimality was confirmed as Sonic started to relax. His eyelids fluttered shut, and his breathing steadied. He was falling asleep, another mobian state.

Soon Sonic's cough subsided into steady breathing. Metal held his palm against the small of Sonic's back, feeling the motion with every breath.

Metal's plan was optimal. He would hold Sonic like this until he recovered. And then they would—they would…

They would fight. Yes, that was it. Metal was sure of it.

They would definitely fight once Sonic was better.