The Italic Parts are flashbacks when Hailey and Jay were kids!

Hailey enters the bullpen and stands by Voight's office door. Voight looks up and smiles.

"Hey Hailey, I'd like you to come meet your new team," Voight says.

Hailey follows Voight into the bullpen, where several cops are gathered. Hailey looks around, taking in the unfamiliar faces.

Jay looked up, from his file.

"Hails?"

Hailey's eyes widened at the familiar voice. She turned to see Jay Halstead sitting at a desk, a file open in front of him.

"Jay?" she said, a hint of surprise in her voice.

Jay smiled, getting up.

"Haven't seen you since kindergarten!"

Hailey couldn't believe her eyes. Jay was one of her oldest friends, they had grown up together in the same neighborhood.

"It's been way too long," she said, returning his smile.

"I can't believe we're working together now," Jay said, still grinning.

Voight interjected, "I thought it would be fitting to pair you two up. Plus, I know you two have history."

As Voight spoke, the other members of the intelligence unit chimed in.

Kim piped up. "Oh, so you two know each other?"

Kevin looked shocked. "You guys grew up together?"

Adam smirked. "That's pretty wild."

Antonio leant on his desk. "Small world, huh?"

Hailey chuckled at the comments. "Yeah, we go way back. Known each other since we were kids."

Jay nodded in agreement. "We were practically attached at the hip growing up."

Hailey, with her blonde pigtails, is riding her tricycle while Jay, with his tousled dark hair, is on a tiny bike. They crash into each other and end up in a heap on the ground, giggling.

Jay laughs at the memory. "I still remember that day at the park."

Hailey smiles. "How could I forget? You had a terrible habit of crashing into me."

Kevin chimed in, "Looks like some things haven't changed."

Hailey joined in on the banter. "Well, at least he remembered my name. Unlike some people here."

Jay pretended to look hurt. "Hey, I always get your name right."

Kim chimes in, "Yeah, yeah. You two are like an old married couple already."

In unison, Jay and Hailey both shot back, "We're not-"

They stop short, realizing what they just said. The group bursts out laughing, Jay and Hailey included.

Hailey fidgets anxiously on Jay's front porch, holding a box of tissues. Jay's mom opens the door and smiles warmly.

"Hailey, thanks for coming to check on Jay. He's been feeling pretty miserable."

She leads Hailey inside to Jay's room, where he's lying in bed looking pale and unwell. He looks up and sees Hailey, giving her a small smile.

"Hey Hails," he croaks weakly.

"Hey yourself," Hailey replies, sitting down beside him. "Looks like you're not feeling too hot."

Jay nods, coughing into a tissue. "Yeah, I feel like crap."

Hailey pats his arm sympathetically. "At least I brought some supplies. And your mom said I could stay for a while if you want some company."

Jay's face brightens a bit. "Yeah, that would be nice. I'm bored out of my mind stuck in here all day."

Hailey grins. "Lucky for you, I can be pretty entertaining."

Jay and Hailey are in the police truck, en route to a call. Hailey is driving, and Jay is in the passenger seat.

As they drive, they fall into their usual easy rapport, joking and bantering back and forth. However, their conversation takes a slightly flirtatious tone without them even realizing it.

Hailey laughs at one of Jay's jokes, glancing over at him. "You know, you're pretty funny when you're not being a pain in my ass."

Jay grins. "You know you love it."

Hailey raises an eyebrow. "You sure about that? I could think of a few other words to describe you."

Jay fakes offense. "Oh, yeah? Like what?"

"Let's see," Hailey says, pretending to think. "Insufferable, cocky, annoying, frustrating... shall I go on?"

"Ouch, Hails. You're brutal. You should be nicer to me, I thought we were friends."

Hailey smirks. "We are friends. But that doesn't mean I won't call out your bullshit when I see it."

Jay laughs. "That's what I like about you, you're always keeping me in check."

As Hailey steps out of the truck, she notices that Jay seems unusually stiff and quiet.

She walks over to him, concern etched on her face. "Jay, you okay?"

Jay doesn't respond, his eyes locked on the small body lying motionless on the ground. He seems to be a million miles away.

Hailey realizes he's having flashbacks from his time in Afghanistan. She gently touches his arm. "Jay. Hey, look at me."

She gently takes his hand and laces their fingers together, speaking firmly but tenderly, "You're in Chicago. You're here with me. You're safe."

Jay looks at Hailey, his voice rough. "Thanks, Hails."

She gives him a reassuring smile. "I got your six, you know that."

Hailey decides to try and help Jay feel better by making him some soup. She heads to his kitchen and rummages through the pantry and fridge, gathering the ingredients she needs. Returning to Jay's room, she sets a pot on the stove and starts cooking.

Jay watches her from his bed, his head propped up on pillows. "You don't have to cook for me, ya know."

Hailey glances over her shoulder, rolling her eyes. "Oh, and let you starve while you're sick? Yeah, right. Besides, it's not like I'm Gordon Ramsay or anything, I'm just making soup."

Jay snorts, suppressing a laugh so he doesn't cough. "Yeah, I'm sure your culinary skills are top-notch."

Hailey shoots him a faux-glare. "Shut it, or you're not getting any soup."

Jay holds up his hands in mock surrender. "Fine, fine. I'll be quiet."

He leans back against the pillows, watching as she continues to cook. Despite his protestations, he's secretly touched that she's going out of her way to take care of him.

As Hailey and Jay return to the bullpen, the rest of the unit notices a difference in Jay's demeanor. He's silent, withdrawn, and his usual friendly self is nowhere to be seen.

Adam looks over at Jay, concern etched on his face. "Hey, Halstead. You good, man?"

Jay gives a half-hearted nod, avoiding eye contact. Kevin chimes in.

"You seem kinda out of it."

Hailey silently observes Jay's closed-off behavior, knowing exactly why he's acting this way.

Back at his apartment, Jay is sitting on his couch, staring blankly at the wall. Suddenly, the doorbell rings, jerking him out of his thoughts. He grumbles and gets up to answer it.

As he opens the door, he finds Hailey standing there, a Tupperware container in her hand.

"Hails?" Jay says, clearly surprised to see her. "What are you doing here?"

Hailey holds up the container. "You didn't think I'd let you wallow in your apartment all alone, did you? I brought pizza and two beers, it's our thing."

Jay hesitates for a moment, then steps aside to let her in. He shuts the door behind her, his expression still guarded.

Jay watches her, smirking.

"What 'thing'?"

Hailey placed two pizzas on each plate, and smirked.

"Well, one of us has a bad day or bad case, the other one comes over to their apartment, we order pizza and beers, we talk and we feel good to come to work the next day,"

Jay takes a plate and a beer from her and they both sit down on the couch.

"You remember that, huh?" he asks, referring to their childhood tradition.

Hailey grins. "Of course I remember. It was our little coping mechanism growing up. You honestly thought I would forget our thing?"

She takes a bite of her pizza, watching him closely.

Jay takes a swig of his beer, then looks at her.

"I guess I just figured we don't do that stuff anymore. We're grown-ups now."

Hailey shrugs. "Grown-ups can still have their traditions, can't they?"

Jay nods, a hint of a smile gracing his lips. "Yeah. I guess they can."

They eat in comfortable silence for a few moments, until Hailey breaks it.

"You want to talk about what's bothering you or…?"

Jay hesitates, then sighs. "It's just… the case earlier. Seeing that kid in the alley… it brought back some memories, that's all. I thought I was past all that, thought I could handle it. But apparently not."

Hailey sets her plate down and moves closer to him on the couch.

"Hey, it's okay to have bad days, you know that. You've been through a lot, Jay. You can't just pretend it didn't happen. It's normal to have flashbacks and triggers."

"Yeah, I know that. But it doesn't make it any easier. I can't turn off my past, Hails. I wish I could, but I can't."

Hailey reaches over, taking his hand in hers.

"I'm here, Jay. I'm always here for you. Always have, always will be."