This took place way back in Season 1, when Casey and Severide were at odds. Imagine this happened right after Casey was mugged by Voight's accomplices. Casey and Hallie were in a relationship, and Severide knew about his neck injury but hadn't reveal it to Casey or Boden.

Casey sighed when he opened the door. The last person he expected. Well, second to last, after Voight's accomplices mugged him on the street. He considered not opening the door, but Severide looked nervous instead of angry so he thought that might be something important. Or something else.

"Can I come in?" asked Severide tentatively as Casey opened the door. "Or there is…"

"What do you want? Check that Heather's here?" asked Casey. Severide's face hardened.

"Never mind." He turned away to leave.

"Sorry," said Casey. "Kelly," he grabbed Severide's arm. Severide dodged by reflex, smacking Casey in the stomach by accident. It was not a strong hit, more like a light slap, but Casey doubled over in pain.

"Casey?" Severide stopped in his track and walked back, uncertain about whether or where he should touch Casey again. "Hey, what happened?"

"Nothing," Casey straightened his shirt as he stood up. "I was out of line. Please," he glanced into the house.

"What happened to your stomach?" asked Severide as he followed Casey inside the house. He could see a scratch on Casey's cheek. "Did you get that on the call?"

"It's no big deal. And what brings you by?" asked Casey.

"I figured it's time we, uh, talk?" asked Severide.

"Go ahead," said Casey. "Beer?"

"Yeah," said Severide. Casey grabbed one from the fridge and put it in front of Severide. Upon Severide's questioning look, he shook his head.

"I'm on painkiller," said Casey.

"I know you didn't sleep with Heather," said Severide. Casey bit his lip, knew that he would let out a sarcastic remark otherwise.

"I have a girlfriend, wherever Hallie and I were, are," corrected Casey, and Severide didn't miss that he saw no woman presence at the house. No woman shoes, no feminine touches Hallie put around the house.

"Right," said Severide.

"You still believe I killed Andy?" asked Casey without beating the bush. Damn. Severide didn't answer quick enough before Casey's face hardened. "I think you need to leave, then," said Casey.

"I didn't say yes, I just don't think it's my fault," said Severide.

"Why does it have to be anyone's fault?" asked Casey.

"Because there are rules, and if we stuck by it, no one would die!" said Severide. "It's not my fault, it's not yours, whose is it?"

"It was Andy's," said Casey calmly. "He entered despite warning. I warned him twice. That's the truth. I didn't say it because it shouldn't be the dead guy's fault, but truth is, it is." Severide's face paled. "You can yell at me, hit me, it doesn't make it any less true."

Severide didn't react for a couple minutes that Casey got worried. He waved his hand in Severide's line of sight. "Kelly," he called. "Kelly, hey!" He came closer to Severide, still being wary that Severide would hit him, either on purpose or accidentally. Finally, he clapped Severide's arm from a safe distance.

If Severide freezing up worried him before, what happened next was perplexing for him. The moment his hand make contact with Severide's jacket, Severide crumpled in his seat, burying his head in his hands. His shoulders shook and he gasped for air between sobs as he cried.

"Kelly?" Casey was beside Severide in an instant, no longer minding the distance. He expected Severide to hit him, but the thought of Severide crying on his sofa with no distinct reason never occurred to him. Sure, he was crying the loss of his childhood best friend, but it was more than half a year ago. He put his hand on Severide's shoulder. "It's okay," he said while patting Severide's back. "Hey, you're gonna hyperventilate," Casey tried to get him to calm down.

"Hhgh…huh…hugh…" Severide muttered in between his sobs.

"What?" asked Casey, although he had an idea of what Severide was trying to say. "Can I hug you, Kelly?" he asked gently. Severide fell to him, putting his arms around Casey's chest. Casey got the wind knocked out of him, after all, he was still bruised from when Voight's accomplices mugged him, but it didn't matter now. Despite Severide's loud and painful wept, he nearly cried with affection when he had his best friend in his embrace for the first time in a very long time. One thing he regretted as much as Andy's death is that he and Severide were at odds during the mourning period. Sure, he had Hallie by his side, however strained they relationship was, she stood by him through the funeral and at home, but he couldn't stand seeing Severide on the other side of the grave, barely able to hold himself together with Shay supporting him. He longed to comfort and be comforted by his best friend. The only best friend he had left.

"It's alright, Kelly, it's okay," Casey continued soothing him, feeling Severide's tears seeped into his t-shirt. "I got you, okay? Whatever it is, I got you," he felt tears started cascading his face as he stroked Severide's hair. "Sorry I wasn't there for you," Casey's voice was reduced to a whisper now. His heart ached now that he knew how much what happened had hurt Severide, and how he kept it hidden the whole time.

"Kelly, are you okay?" asked Casey when Severide's cry finally died down. Now all that left was little sniffles here and there. Severide shook his head. "Anything hurt?"

"I hurt you," muttered Severide.

"I'm okay," said Casey. He wasn't, but witnessing Severide's grief was already too much for him, he didn't think he could handle the guilt that was coming.

"It's not true," said Severide, his voice was still muffled by Casey's t-shirt, which now had been soaked wet from Severide's tears and probably snot.

"It wasn't true, but it is now," said Casey. "I wasn't innocent either, I was out of line on many occasions."

"I don't even know who I am anymore," said Severide.

"Hey, look," Casey peeled Severide off him and forced Severide to lock eyes with him. "Look, you're still you. You ran your mouth and you got emotional more often than girls on period, but you were one of my best friends. And that friend was missed a lot lately. I hope we're still friends, though."

"Yeah, me too, if you're… willing," said Severide.

"Come here," said Casey, and Severide latched onto him once more, sobbing more intensely that Casey became worried that he would throw up eventually. In his nearly 10 years of knowing Severide, sharing an apartment at some points, he knew that the bad boy persona was only on the outside. Inside, he's like a giant teddy bear who cried after the most gruelling rescues and dead victims. During candidacy when they were sharing a flat together, after bad calls like suicide and dead kids, Severide would cry in his sleep and Casey would climb to his bed and calm him down.

"Breath, Kelly," said Casey, soothing Severide and rocking him slightly. He never saw Severide shaken this bad, even after a 15-hour gruelling rescue which left two colleagues and 15 victims dead. Severide didn't seem to hear him, and kept tightening his hands around Casey, grabbing a handful of fabric on his back while unknowingly hurting his back further from the mugging. Still, Casey didn't care. Severide could crush his ribs if he needed. Finally, after what felt like forever, the sobbing stopped.

"You okay?" he asked just after he pulled back from the hug and saw Severide's pale face and bloodshot eyes. He could see how draining it was for Severide who was now sprawled on his sofa.

"Good," said Severide.

"You're not," said Casey. He smelled alcohol from Severide's breath, and he knew Severide had been drinking before he arrived. Given the half a bottle from Casey's fridge and his condition, Casey didn't trust him to drive home. "Rest for a bit, Kelly. You're about to pass out."

"Weneed talk," stuttered Severide.

"We will, not now," said Casey. "Have you had dinner?" Severide just shot him a blank look. "Okay. Lie down," said Casey. He wrestled Severide into a laying position with no resistance, and took his shoes off. From the cabinet he pulled out a blanket that had been shoved there since Heather stayed over, and spread it over Severide who was already fast asleep. He couldn't resist himself and planted a soft kiss on Severide's hair.

"Love you, brother," he whispered, his tears fell after he said it. He lost two brothers when Andy entered the doomed house, and finally, he got one back.

Severide stirred when he woke up in a strange place. It wasn't his first time waking up in a random place, but it's usually a woman's bed, not a sofa. His head felt drowsy as he looked around. When he tried to speak, he squeaked. His throat felt dry and his eyes were warm.

"Headache?" asked Casey. He would be doomed if Severide was under alcohol influence last night and forgot everything that happened, and went back to the enemy he had been for the past six months. Tentatively, he lent a hand to help Severide haul himself off the sofa.

"Massive," croaked Severide. He used Casey's hand to help him sit, but he was hit with a strong headache. He grabbed his head and let out a small dry retch. He clasped his hand on his mouth.

"Need to vomit?" asked Casey. He shook his head lightly, concentrating on Casey's hand which had found its way to the back of his neck and gave his nape a squeeze. He felt his head bumped into something, and by peeking with one eye he knew that Casey had knelt in front of him and supported his head with his shoulder.

"Damn," he said when he was finally able to look at Casey who had worry on his face.

"You remember what happened?" asked Casey.

"Yeah. Sorry I… went out of control," said Severide. He stood up and followed Casey to the kitchen. He smelled coffee and saw that Casey was preparing pancakes, the one on the stove was slightly more burnt than the others because Casey left the stove on.

"It's alright," said Casey. When the coffee was ready, he handed a mug to Severide, followed by a glass of water and two aspirins. "How much did you drink before coming here?" Severide shrugged his shoulders.

"You don't have to," Severide glanced at the pancakes.

"I know, I want to," said Casey.

"What did I do last night?" asked Severide.

"Nothing that hadn't happened before," said Casey. "Can we put this," he gestured to both of them, "to rest? Put it down as one bad shift, that will never happen again? It's a matter of losing one or two friends."

"Yeah, I agree. Whatever we do, Andy will never come back," said Severide. He surprised himself by saying that easily. "And we'd only push each other away. I'm sorry, though. For accusing you of… and for everything I said. I don't know why you still," he motioned to the sofa, a bit surprised that Casey took care of him instead of kicked him out, but that's just who Casey is as a person.

"I owe you an apology, too. I forgot Darden was your childhood friends, I didn't try to be there for you after the accident. I saw you at the funeral but didn't think you'd appreciate if I came over, or anything. In the end, I didn't reach out to you," said Casey.

"Can see where it came from," said Severide. "I didn't remember anything, though. Spent the night before funeral in a bar… forgot where. Shay dragged me back to the apartment, spent the morning on the bathroom floor, I think. Bless her heart."

"I miss you, Kelly," said Casey. "Wondered what would you say when I broke up with Hallie, all that crap about settling down."

"What happened? Why did you move here?" asked Severide, looked around the house.

"A lot happened. We're back together now, not engaged, I think," said Casey. "Anyway, what brought you here? I mean, why now, out of nowhere? Chief said anything to you?"

"We had a rescue yesterday. Two women, they were friends, they fought in the car… a concrete fell on the car. One died, one lived. They fought for two minutes. And I thought… six months. It's been too long," said Severide. Casey nodded. He understood Severide's reaction yesterday.

"Eat up," said Casey, dropping two plates of pancakes on the table. They ate in silence until Casey asked, "you have plan for today?"

"No," said Severide. "Why?"

"You still look like hell," said Casey.

"Yeah, not feeling too hot," said Severide. "Probably the alcohol. I'll go home and sleep."

"You alright to drive? I can drive you home," said Casey.

"I don't have my car anyway," said Severide. Casey frowned. "I walked here from the bar at the corner near the school. Left my car at home," said Severide. "Hey, what happened to the face… and yesterday, outside? Your stomach?"

"Ah, Voight," Casey spat. "Tried to threaten me to retract my statement… sent people to mug me."

"What?" asked Severide.

"It's no big deal," said Casey. "No major damage anyway, it's alright."

"Let me know if you need help beating him up," said Severide. He pushed his plate with a few pieces left. "Normally I'd demolish it, but not feeling the best today."

"It's okay," said Casey. He reached across the table and felt Severide's forehead. "You're fine, I think you're just hungover. Finish your coffee, I'll drive you home."

Severide sipped his coffee, trying to remember when was the last time Casey and him spent time together, just the two of them. Deep down, he always felt there's a connection he shared with Casey, even if Darden was always with them. Darden came from a close family, his parents were still together, he was in routine contact with his siblings, and he had a wife and children. He always felt like a lone ranger until he met Casey, who was more estranged from his family. Casey always dodged conversations about family. His dad was dead, his mum was in prison for killing the aforementioned dad, and who knows if there's any siblings.

"What?" asked Casey.

"No, it's just… been a long time," said Severide.

"Yeah, I know," said Casey. "Since the Blackhawks' game, they haven't won any game since then," said Casey. "Remember? You came an hour early and Hallie almost killed you with scalpel for interrupting us?" Hallie likes Severide, Darden, and Heather, but Severide coming in the middle of dinner before a 26-hour shift was something she didn't tolerate, she locked Severide in the guest room until they finished eating and making out.

"So, we need to watch together again, to earn them the win?" asked Severide.

"We'll be doing it for the city of Chicago," agreed Casey. "You'll come tonight, I'll buy pizza."

"Deal," Severide stood after finishing his coffee. He stood to grab his jacket from the sofa. "Hey, this may be out of nowhere, but have I ever told you I love you?" Casey stopped putting dishes in the dishwasher to ponder about the question.

"I don't know," said Casey, taken aback by the sudden question. Severide felt like he was stabbed right in the heart. "Doesn't matter, though. I know it."

"Well, just feel I need to make sure you know. You are a brother," said Severide.

"I always know. And it's mutual. However much I resented you at times, I still love you, brother," said Casey. He walked over and pulled Severide into a hug and sighed when he got squeezed back in return. It wasn't an emotional teary hug like last night, but a brief, firm one. "We're gonna be okay, Kelly."

"Oh yeah we are. Surprise to everyone at 51," said Severide, clapping Casey on the arm. They got into Casey's truck and drove to Severide's apartment. When they arrived, Shay just pulled over in front of them. She didn't see them as she was busy playing tongue twister with a girl immediately after she got out of the car. They watched with amusement when the girls walked into the building. Severide groaned.

"Well, that's it for sleeping off the hangover," he rolled his eyes.

"Back to my place?" asked Casey. "You can sleep off the headache on the sofa. It's not like I'll have anyone to make noise with."

"No random girls?" asked Severide.

"I'm not you," said Casey. "I'll paint the upstairs bathroom today, which has pretty thick door and there won't be much noise."

"In that case, please," said Severide. Casey drove back to his place, and after closing all the curtains and making sure Severide was comfortable and got his clothes to change into, he went upstairs to fix his bathroom.

Severide slept all the way to noon, and when he woke up, he saw a takeout box on the coffee table. There's a very subtle noise from upstairs, but unless he strained his ears and listened carefully, he heard nothing. He smirked when he opened the takeout box and saw fried rice, his favourite. It's funny how fast things got back to normal, they didn't even yell at each other and decided to just pick up where they left off before the accident. He wondered what made him wait six months to actually came with a cool head and no desire to hit or yell at Casey. Now, he just needed to tell Casey about his shoulder, which he didn't think Casey would take well.

"You okay with that?" asked Casey. Severide looked up and realised he zoned out.

"Yeah, yeah. Thanks," said Severide. Casey took a scissor from the kitchen then walked back up. After he finished eating, he grabbed the remote and turned on the TV.

They watched Blackhawks while having pizza and beer, and to their surprise, Blackhawks won for the first time in six months. They had identical huge grins on their faces as Casey turned off the TV.

"See, we're the lucky stars!" said Casey.

"Yeah we are!" said Severide. "So, do we have to watch it together on every match?"

"For the city of Chicago, Kelly," said Casey. They burst out into laughter.

"I don't think you can drive me back," Severide pointed out as he cleaned out the table. There were seven beer bottles shared between two of them. "I'll call a taxi."

"I'll drop you back tomorrow morning, it's not like you have anyone waiting on your bed," said Casey.

"Ouch," said Severide. "You have no idea that I got engaged and married in the last six months, Casey."

"Huh. Really. In Vegas?" snorted Casey. "Or you hit your head?"

"Fair enough," said Severide. "Night, Casey. Don't let the bed bug bite." Casey didn't turned back from the stairs, just continued laughing.

"Night, Kelly."

Casey was cooking in the firehouse kitchen when Severide strolled in. Some eyes were immediately on him, anticipating the bitter spat between the two lieutenants. Severide poured a cup of coffee for himself and glanced at Casey. They hadn't bumped into each other in the firehouse, so the other had no idea that things had changed.

"Corned beef?" asked Severide.

"Yep," said Casey.

"Nice," said Severide, then strolled outside. Herrmann and Otis' eyebrows were up witnessing the conversation. "Run drills?" he asked in a low voice. Casey waved his hand. "Squad, truck, let's run drills outside!" While members of squad moved, members of truck didn't and looked at Casey. They've been a divided house for a while that they never did anything together beside joint calls.

"Come on, move your ass! Cruz!" Severide slapped Cruz' back. Casey looked up from his corned beef.

"You heard him. Go, I'll catch up in a few," said Casey. Their faces lit up.

"So…" said Otis.

"Yeah, it's a combined drill. Go," said Casey. After everyone scurried away, Severide followed them and threw a look at Casey who returned a smirk. Casey put the meat in the oven and went outside. It was freezing outside, but for the first time, things seemed normal. Cruz and Capp were joking while they rolled out a hose, and Otis crawled behind Tony.

"Haven't done a drill that tiring, I kept hoping for the alarm to go off," said Mouch as they piled up into the common room.

"You have to earn the meat," said Casey who left the drill earlier to continue cooking. He took the meat out of the oven and served it on the kitchen counter with some potatoes and vegetables. "Dig in."

"You eating, Lieutenant?" asked Otis. Last time, Severide snubbed the corned beef and ate a banana instead. No one knew that later at night he dug up the fridge and had the corned beef.

"Yeah, you don't?" asked Severide. He piled up a couple pieces of meat on his plate.

"Hey, so…?" Herrmann left his words unfinished. "Is this a ceasefire or should we be expecting anymore war soon? I need a one shift notice before situation changes."

"Ceasefire from what?" asked Casey.

"From whatever it is you two have been going for months," said Boden who entered the room at the right time.

"I don't know what you're talking about, Chief," said Severide.

"Yeah, nothing's going on," said Casey. "Corned beef?" he offered innocently.

"What's going on, Chief?" asked Severide.

"Huh," commented Otis who followed behind Severide in the line. Everyone was confused, trying to figure out if they misremembered the situation, that for six months since Darden's death the two previously best friends had been fighting with each other, raising the temperature inside the firehouse, and basically splitting truck and squad members. And now that they've gotten used to the 'new normal', suddenly it's back to the 'old normal' which they couldn't remember anymore. Half of them felt dejavu sensation, the other half felt straight up confused. Seeing the perplexed look on their faces, Casey crouched behind the fridge, laughing silently. Severide who saw him couldn't hold his laughter. Boden slapped him on the back. Severide sat on the ground, still laughing.

"Not funny," chastised Herrmann. Casey joined Severide in laughter.

"Yeah, we're good, Chief," said Casey after he managed to contain his laughter and walked around the table. He lent his hand to help Severide standing, and he didn't miss Severide's slight wince as he pulled him up. Promising himself to ask about it later, he clapped Severide on the back. "Well, brothers fight." He pulled Severide into a side hug. Everyone looked relieved and started smiling

"About time!" someone whistled and clapped. Casey felt himself blushing and he glance at Severide who looked sheepish.

"If Lee Henry and Luke ever fought for half a year, I'd slap their asses to Florida," grumbled Herrmann.

"Agree. Lieutenants, after you're done eating, wash all the windows in the apparatus floor, and redo the supplies cabinet," said Boden.

"What? Seriously?" asked Severide.

"Anyone want to add to the tasks? That's what you got when you put the house in misery for half a year," said Boden.

"Cook for the next week?" suggested Capp. "I mean Casey, but you can help, Severide."

"Uh-huh," mocked Severide.

"And do squad's inventory," added Tony.

"Truck too," added Mouch.

"I told you to do that," protested Casey.

"Okay. Better start eating now, the axes are not gonna count and sharpen themselves. You have two shifts to do all that," said Boden.

"Copy that," nodded Casey. "It's your fault, Kelly, why did you laugh?" he grumbled.

"You started laughing!"

"You rolled on the floor!"

"Well, I didn't have a fridge to hide into!"

"BOYS!" Herrmann shouted.

Just a short one. I actually enjoy writing longer ones, but this was quick to write!