Hey guys, I'm bacccckkkk! Thank you to everyone who has reviewed, it truly truly makes me so happy!

Sorry for the longish update, I actually had quite a lot of this written and then lost it all D': So I apologise if the end isn't too great. I feel like I kind of take these one-shots and write too much, but I honestly get so invested, it's like a sickness haha!

Coming up with the plot for this one was actually quite tricky, but I hope you all enjoy how I did it.

Thank you to the Bubbly88Tay for submitting this prompt, (I changed the wording slightly I hope that's cool):

"You'll hurt me. You'll hurt everybody, but most importantly, you'll hurt me."

Jay stared into contents of an empty refrigerator for far longer than humanly normal. With each second his stomach growled louder, and he was beginning to regret slacking on his grocery shopping recently. Unless he could whip something up from a strip of bacon and a drizzle of questionable milk, he was going to need to order takeout.

Just on queue, Jay's phone rang out from across the room. As he made his way over he already had a dinner in mind - Pizza from across the street. Assuming it was Erin calling before he even reached his phone, Jay knew that his partner had his pizza order memorised, so he would simply beg her to drop by with the hot food as soon as she could.

Surprisingly, he saw a different name on the screen. Even more surprisingly, he hesitated before taking the call. That wasn't something he normally did when it came to Allie Corson.

"Allie, hey." Her name still sounded strange on his tongue, even after all these years. Even after all they'd been through.

They'd speak over the phone every few weeks, or every time she took a trip back to Chicago to visit her parents. Sometimes their conversations were filled with silent voids, aching hearts still brokenly beating over a murder that happened seven years ago. But sometimes they'd talk for hours, forgetting a single second had passed since their High School romance.

"Hi." She sounded occupied and distant. No one said anything for a few more seconds and Jay assumed it was going to be another one of those melancholy calls. Then Allie spoke up. "I need to ask you something."

"Okay," Jay said, leaning on the side of his sofa as he pressed the phone closer to his ear. "Shoot."

"You remember when you told me to stay in Chicago?"

"Yeah." He couldn't forget it. He'd said it with a childish hopefulness that he'd somehow be enough to make her stay, while deep down he knew the words were futile. For Allie, Chicago would always be the city her baby brother was murdered in. He couldn't hold it against her for wanting to escape.

"Well... I want you to come to Phoenix." Her voice drifted out and Jay wasn't sure he heard her right.

"Move... To Phoenix?"

"Yeah." He exhaled loudly without thinking. "Look, I know it's a big ask and I don't expect you to give me an answer now, but... I feel like this could be good for us."

He ran a hand through his hair, the rumbling in the pit of his stomach suddenly disappearing. The blood was thumping in his head and he couldn't think straight. Things weren't going great for him at the moment, but they were going well enough. And moving to Phoenix would definitely upset the balance of it all.

"My job's here, Allie. My life is here." Jay noted how when he thought about it, his life was his job.

"You could transfer. We have a great Police Department over here, and I think you could do well. I... I think you could be happy here, Jay."

He wanted to tell her he was happy in Chicago, but maybe that wasn't exactly true. Maybe there was something that felt numb when he came home late at night to an empty apartment.

"Allie-"

"Don't give me an answer tonight. Sleep on it." Her voice sounded nice in his ear, familiar. It wasn't a sad voice either; it was hopeful. It was the voice he heard late at night when he thought back to the two of them - Her nervous optimistic voice as she asked him to prom, knowing he'd never pluck up the courage. He smiled at the memory. He smiled at the thought of being a blissfully ignorant teen, ready to take on the world with the girl he loved. Maybe things could go back to that.

"Jay?" She asked. "You still there?"

"Yeah..."

"I know I'm asking a lot. Trust me, I know that. But... We both deserve to be happy. And I think we can make each other happy, here in Phoenix."

"Chicago's my home now, Allie." He heard her breathing softly through the line.

"There's this great little burger joint just five minutes from my place. And down the street there's this cute like cake shop. You'd love it."

"Are you trying to fatten me up?" Jay asked.

"Don't worry, there's an amazing gym only a couple of blocks away. And I'm pretty sure I can think of other forms of exercise too..." Jay laughed at the insinuation. Allie laughed too. It felt like home.

"God, I miss you." She breathed. "I'm crazy, I know. What I'm asking is crazy. Just please, Jay, tell me what you're thinking." He was thinking that when they ended in their call, he'd crash in an empty bed, alone in the dark. Allie would be too. Maybe bringing two broken hearts together was the smartest move.

"I'm thinking... I miss you too." His home was Chicago. But maybe Allie could be his home.

"Call me tomorrow?"

"You got it."

He put the phone down on the table and ran hands through his hair. His fingers dug into the roots as he forced his eyes shut. It was a lot to think about.

He opened his eyes and looked round his darkened apartment, feeling suddenly cold in the silence. Just then, his phone began buzzing again, vibrating on the table. He looked over and saw his partner's name flashing on the screen. He suddenly felt sick.

He watched her name continue to flash and willed himself to take the call. To talk everything through with her. To let her help him.

But as he reached out a hand, it froze centimeters from his phone. He watched her name fade away and the painful 'One Missed Call' flash before him.

Jay swallowed the lump in his throat as he contemplated calling her back. He couldn't believe he was even considering all of this without speaking to his best friend. He couldn't believe the idea of moving miles away from Erin never crossed his mind as he spoke to Allie.

He thought of Erin; who she was and what she meant. She was Chicago. She was the entire reason Jay was tied to the city.

In the darkness, he felt her hand in his and heard her laugh in his ear. He bit back a smile as the hallucination drifted away, leaving him with nothing. Nothing except an offer from an amazing woman with whom he shared a history with.

He rubbed the palm of his hands into his eyes and tried his hardest to calculate everything.

Erin was with Kelly. She was happy. He could complicate it all he wanted, but that's what it was. Erin didn't go to sleep at night with the optimistic hope of 'One Day' fluttering in the back of her mind; she went to sleep next to her fireman. Jay was sick of going to sleep alone.

So that was it. In the space of five minutes Jay had decided his future. A future with Allie. A future in Phoenix.

Erin was running late the following morning, cursing the relentless queueing in the local coffee shop as she climbed the stairs to Intelligence. Her foot hit the hard ground and she walked in between the row of desks, two cups of coffee in hand as she passed her unit.

She nodded to Dawson as she passed his desk but she barely got a look back.

Erin was surprised to see Halstead's desk empty. So simply thinking he must've overslept, she placed the coffee with extra sugar on the edge of her partner's desk before rounding on her own. After placing the cup in front of her keyboard, Erin stripped her leather jacket from her body and hung it round the back of her computer chair.

There was a thick atmosphere as she sunk into her chair, barely taking a sip from a well deserved beverage before Voight wandered out of his office, his expression stonier than usual.

"It's dead today. We're on paperwork and if you're lucky, you'll all be outta here by five."

Nobody groaned out loud but Erin could feel the internal moans from everyone around her. She hated this part of the job; she signed on for the action, not for the secretarial temping.

As she reached out a hand to grasp the file on the edge of her desk, Erin raised her voice. "Anybody seen Halstead?" She asked absently, opening up the yellow case file while reaching for her cup with the other. She'd called Jay the night before but he hadn't picked up. And strangely, he hadn't called back either. She wasn't worried though; she just assumed he'd met up with some random girl at a bar and taken her home. And if that was the case, she wasn't jumping to hear the details.

She heard Hank inhale deeply, causing her to lift her head. He slowly folded his arms across his chest and looked to the ground.

"Halstead's transferred. Effective immediately."

Erin snorted. Then she saw the hard look in Voight's eye and she felt her jaw slacken. "What? Is this a joke?!"

"No, no, no..." Ruzek started, shaking his head with disbelief. "There's no way in hell he'd transfer?"

"Transferred to where?!" Erin asked, her voice booming.

"Phoenix. Spoke to him this morning, he seemed pretty adamant."

"Even if Jay did want to transfer..." Antonio began calmly, his voice of reason resonating above the uproar. "With the paperwork needed, it'd be weeks, months..."

"He called in a favour with the DA. As of 7am today, Halstead was no longer part of this unit."

Erin felt numb as the questions and answers continued. She bit down on her lip as she stood up from the chair, grabbing her jacket and sliding it on as she walked. "Screw this." She muttered as she walked past her unit, the voices of her co-workers attempting to reign her in.

Jay was surrounded by boxes; he was amazed at himself how much work he'd gotten done. He wanted to leave as quickly as possible, and that seemed to be motivation enough. Leaving the morning after Allie's offer seemed bizarre at first, but Jay soon decided that if he was leaving Chicago, he didn't want to drag it out.

Just as he finished taping round a cardboard box labeled 'BOOKS', a loud knocking vibrated through his door.

"Open this door, Halstead." He recognised that angry tone anywhere. "Open it right now or I'll knock it down, and you know I'm not joking." He sure as hell did. Jay had seen Erin do far more impressive things than kick down a wooden door.

With a sigh, Halstead stepped over several packed boxes until he got to the door, momentarily bracing himself before swinging it open. Erin looked hasty and out of breath. Jay wasn't one to talk though, he was pretty sure he looked like hell. Being up half the night packing certainly took its toll.

They stood simply looking at each other for a few seconds, breathing in and breathing out.

Saying Erin looked angry was an understatement. Jay was pretty sure he could see smoke rising from her ears. Before she uttered a fuming word, Erin stormed past her partner and into his apartment, before freezing at the sight before her.

Jay watched as she took in the several boxes, with most of his apartment stripped of anything vaguely personal.

"What the hell?!" She asked, turning to face him with a hard face. He felt himself shrink under the severity of her gaze.

"I wanted to tell you, but-"

"But what?! Why the hell are you doing this?"

With a sigh, Jay closed the door, shutting them both in. He slipped both hands into the pockets of his jeans and took a few steps closer to his partner. He wished he'd called her back the night before. He wished he wasn't having this conversation with her.

"Allie called. She wants me to move to Phoenix."

Jay had told Erin about Allie a few months ago over a few too many beers and Molly's. He'd told her everything about the Lonnie Rodiger case too. And she understood; she reached out her hand and held his tightly with reassurance and understanding.

"So you're doing it, just like that?" Erin asked, clearly offended by his blatant spontaneity.

"I've thought about this, Erin. It's the best thing for right now." The words coming out of his own mouth sounded absurd. Desperate to break some of the intimacy off, Jay walked past his partner and towards the sofa, absently packing miscellaneous items into an empty cardboard box.

"According to who?" Erin scoffed, following him. "Allie? If she thinks that moving you miles away is the best thing then she clearly doesn't know a damn thing-"

"Don't pretend you know a thing about this." Jay told her coldly, sending a defining glare in his partner's direction.

"How could I possibly know when you never let me in?!" Erin practically screamed, her face reddening slightly.

Jay's chest rose and fell to the time of Erin's, both of them with burning lungs. Jay knew he was closed off, despite the fact he didn't want to be. He knew Erin wasn't the type of girl to bare her soul, and yet there were times when she did it so easily to him. But he found it so difficult to do the same.

"I'm moving to Phoenix." Jay told Erin with confidence. "I have to do this."

"What about the rest of us? What about your unit?"

Halstead bit his lip and looked to the ground. "Don't pretend I'm some key component, Erin. We both know I'm far from a necessity." He tried to smile but he couldn't muster it.

"What are you talking about?" Erin asked with a suddenly softer voice, taking a step toward Jay and touching his arm lightly. "You're a part of our team." Jay didn't seem impressed. Erin continued. "Jin was murdered. Antonio hasn't seen his kids in weeks. And you're just going to bail?"

"I'm not bailing! I'm tired of putting this job first." He seethed. He knew he was thinking of Voight's ridiculous 'no in house romance' rule. For once, he didn't want to job to get in the way of everything. "I need to think about myself, for once." Jay didn't mean for his voice to stay so cold, but it was. Maybe a part of him wanted Erin to give him a reason to stay, not that he'd ever admit that.

He looked at the hurt in his partner's eyes and his mind flickered to her words of 'One Day'. He wanted to reach out to her but he couldn't move. He felt Erin remove her hand from his arm and step back, tucking her hands into her own pockets.

"Do you love her?"

"What?" Jay asked, the question taking him by surprising.

"Allie. Do you love her?"

"It's... It's not as simple as that." He did love her once. More than he thought he'd ever love anybody. But then a murder happened and they drifted apart in the worst way. But he had a feeling he could love her again, if they went back to their High School selves.

Erin paused and Jay heard her gulp, almost bracing herself. "You remember Annie, my old best friend?" Jay nodded. "I love her. So much. But... Everytime I look at her, I see Sandoval. And everytime I look at her son, I see Charlie. I've tried running from my past, Jay, and I've tried getting it back too. But it's called the past for a reason."

And just like always, Erin managed to read Jay better than anyone.

"I'm begging you to stay in Chicago." Erin stated bluntly. "But if you do want to go, I just hope you're doing it for the right reasons."

She began walking backwards slowly, her voice growing softer as she did. Finally, right by the front door, Lindsay stopped and sighed.

"You're my best friend. I haven't said it lately, but it's true. If you do this, Jay... You'll hurt me. You'll hurt everybody, but most importantly, you'll hurt me."

Jay tried to call out to her, to say anything worth saying. But as usual, his throat closed up and he could do nothing but watch her leave.

Jay sat outside Molly's, his engine on and raring to go. He sat back in the driver's seat, his eyes drifting lazily from sleep deprivation. The city was growing dark but Molly's was lighting up, ready to accommodate the city's guardians for a night of after-work drinking.

Jay felt his hands tense up on the wheel, his foot aching to touch the pedal. Then he saw Erin. And all his muscles relaxed.

Even from across the street, Jay could see she was exhausted; the way she carried herself was weighted and her legs looked strained. Her hair blew around her face and her jacket was hugged tight around her.

And suddenly, Jay knew what to do.

Watching Erin open the door to Molly's, Jay pulled his phone from his pocket and dialled a contact, consciously telling himself it would be the last time he'd call that number.

"Hey," Allie's warm voice greeted him. "Tell me you're almost here."

Jay smiled sadly to himself, pressing the phone to his ear. "I can't come to Phoenix, Allie." He could hear her exhale with disappointment. "I'm sorry. I just... I've been wanting to get back to the 'old us', and I thought this would be the way to do it, but... There is no 'old us' anymore, there's just us."

He paused and Allie kept quiet. He felt sick again, but deep down he knew he was doing the right thing. It was Erin who made him realise that.

"If things were different, we'd be great together. But... But everytime I look at you, I see Ben. And I know you do the same. It tore us apart for a reason."

He heard Allie crying quietly on the other end of the line. He even felt his own ducts filling. He was finally saying goodbye.

"I can't convince you to come?" She asked. There was futility in her voice.

"We're not in High School anymore, Allie. I think we have to move on." He finally said it.

A few sniffs later, Allie spoke again. "So this is goodbye, huh?"

"I guess so."

"Be happy, Jay."

"You too. You deserve to be happy." Jay said, feeling some part of him begin to break away with his words. "We both do."

Erin took a sip from her frothy beer, while her heart had remained deep down in her chest. She fingered the cool glass and kept her head down. The thought of Jay in Phoenix at that very moment brought a sickness to her stomach. She didn't even get to properly say goodbye.

It hadn't even properly sunken in; the fact she'd never see his face every morning or hear him laugh in their car rides. She'd never watch his eyes roll or hear one of his dumb jokes. She'd never get any of it again, and she hadn't even said goodbye.

Her fingers were icy cold around her glass but she couldn't let it go. That was until she heard the voice that made something inside her quiver.

"This seat taken?" Jay asked, hovering by her. She felt a smile break out across her face.

"You're staying?" The coy smile on his face told her he was, but she knew her partner. She knew he wanted to have fun with it first.

"That depends..." Jay said vaguely, reaching out a hand and drawing his partner's beer closer to him. "You gonna let me drive?"

Erin willed herself not to smile so broadly, but it was inevitable. "Not a chance." She told him with a smile. And almost infectiously, his jaw softened and the corner of his mouth relaxed, easing into a comfortable grin.

Erin realised then, that not for the first time, she'd almost lost Jay Halstead. Yet, like always, he always managed to find his way back to her.