Hi there! This is my first Chicago PD story, since I only just started watching the show. This story really just fell out of me once I started writing. I've fallen so in love with Erin and Jay. I've written this before the PD/SVU crossover airs, based only on the synopsis information for Law and Order: SVU 17.14 'Nationwide Manhunt' and Chicago PD 3.14 'The Song of Gregory William Yates'. I hope you enjoy it.

/

The bullpen in the Intelligence Unit of the Chicago Police Department is tense. Everyone is furiously working on something, the detectives of New York's SVU team helping amongst them all.

Lindsay stands suddenly and makes her way to the break room. Halstead lets his eyes follow her retreating form, his brow furrowed in concern. He's been worried about her all day, a few days really, since they heard of Yates' escape. He'd worried about her the entire time that she was in New York with Antonio, and his concern hadn't diminished once she'd arrived back in Chicago. She'd barely slept the night before. He had stayed up holding her until exhaustion had claimed him, and she'd been in the exact same position when he awoke only a few hours later.

He sighs heavily. They're generally very good at keeping the boundaries between their personal and professional lives separate, but now is a circumstance that makes that rather difficult. He'd still be worried if she was only his partner, not his girlfriend, but he knows what this case has the potential to do to her, how much pain she's already had to endure this past year. Added to the fact that he loves her desperately (not that he's voiced those feelings yet), he's definitely concerned about her wellbeing right now.

He stands and makes his way to the break room, where he finds he slouched over the counter, weariness evident in her stance.

"Erin." He calls to her softly.

She lifts her head to look at him. Her eyes, which have been filled with anger and determination all day, are now glassy with unshed tears. His heart breaks at the sight because his Erin rarely cries, and it kills him whenever she does. She looks so much smaller than her usual vivacious personality.

He steps forward, needing to be closer to her.

"Are you okay?"

It's a stupid question to ask, and he knows it as soon as the words leave his lips, but he has no idea what else to say. He wants to make everything better for her, but he doesn't know how.

She shakes her head at him desperately.

"Don't."

"What?" He asks in confusion. He knows she's a walls up, shut people out kind of person, but she's been better with him the last few months.

"Please don't. I can't do this right now. I'm not okay but I have to be right now. I can't stop and think about how I'm feeling when he's out there, probably hurting more women. I need to focus so we can get this son of a bitch and put him in the ground where he belongs. When we've done that and we go home, that's when I can be not fine, and you can be your normal perfect self and worry about me. But please don't ask me if I'm okay right now."

He understands perfectly. "Okay."

She nods back. "Okay."

He takes the last few steps towards her, restraining the urge to pull her into his arms. He knows if he does, she'll fall apart. Instead, he reaches out and grips her arm with his hand.

"We're going to get him." He says determinedly. "We'll get him and make him pay for what he's done, and then we'll go home." He squeezes her arm reassuringly.

She gives him a hint of a smile. "Thanks." She tells him softly.

They stand together for another minute before heading back out into the bullpen, ready to continue fighting the good fight.

/

They get him the next day. Voight brought some of his personal sense of justice, as always, and the serial killer left the world at the hands of Erin Lindsay's gun.

As soon as the shots went off and he was confirmed dead, Voight had taken Lindsay aside and held her shaking body. Jay had watched on, witnessing the interaction between father and daughter. Voight had waved him over soon enough.

"Take her home, Jay," the Sergeant orders in his usual gravelly voice. "Get her away from this."

Jay nods at the order, more than happy to do so, and wraps his arm around his still shaking partner, leading her back to the car.

They sit on the couch at her place, silence hanging over them. Erin still hasn't said a word since before she pulled the trigger.

Eventually, the tears start to fall, cascading down her face until the sobs take over her body.

Jay slides closer immediately, pulling her into his arms and holding her against him tightly.

"I know," He whispers against her hair. "I know." He can't tell her it's okay, because it isn't. Nadia's still gone.

"I just – I can't –" She stutters through her tears.

"I know, babe." He kisses the side of her head, sadness gripping at his heart. "I'm so sorry."

"I just wish she were here." Her small voice barely reaches his ears.

"Me too." He swallows the lump in his throat. "But she would have been proud of you, I know she would."

They fall into silence and sit there for however long. Jay doesn't make any attempt to move, knowing that she'll let him know when she's ready. He doesn't dare offer her a beer or get one for himself, as they usually do. After a week like this he'll be watching her for a while to make sure she doesn't fall back down the dark hole she climbed out of recently.

Her weight against him grows, and he knows she's succumbing to the exhaustion she's been fighting the last few days.

"Come on." He stands and pulls her into his arms, ready to carry her to bed. She rests her head against his shoulder, silent as he makes his way to her bedroom.

He deposits her onto the bed and sets about removing her shoes and jacket. He helps her change into a shirt and shorts to sleep in, and holds the sheets open for her to crawl under.

He turns to move away, but her hand on his wrist stops him before he can take a step.

"Stay." Her voice is even raspier than usual. "Please."

His heart clenches again at the sight of his strong girl so beaten down by the world. He moves closer to her again, cupping her cheek with his hand.

"Hey, no way am I leaving." He says firmly. "I'm just going to check your front door, okay?"

She nods, feeling foolish for being so needy. He leaves and returns in under a minute, placing a glass of water on her bedside table. He strips off his clothing and pulls on the sweatpants and t-shirt he's started leaving there for sleepovers, before joining her under the covers.

They lay on their sides facing each other. He reaches out to stroke her cheek, pushing her hair away from her face.

"I can't sleep." She confesses in a whisper. "I'll see it again."

Whether she's referring to her usual nightmare of Nadia's body in the ground, or the fact that she killed a man only hours ago, he's not sure. Either of them are enough to keep her awake all night.

"I know. Just try to sleep. I promise I'll wake you if you have a nightmare." He tries to soothe her, calm the fear in her eyes. "You're safe with me, Erin."

His words seem to work. She wriggles closer to him, pressing her body against his. He reacts on instinct, wrapping an arm around her waist.

"I know." She replies simply.

Her faith in him warms his insides. He loves this girl so much, and all he wants to do is shield her from the cruelties of the world. She's finally starting to believe that he's not leaving, not for anything.

The nightmares do come, and he wakes her and holds her through each of them, doing whatever he can to help.

She wakes herself when the sun rises, still tired from her fitful sleep, her heart still heavy. It doesn't seem to matter quite as much when she looks upon Jay. This beautiful man sleeping next to her looks just as exhausted, since he spent all night helping her. He's so good to her.

Nadia would be proud of her, she decides. Not just for finding the man who killed her and staying away from the drugs this time, but for allowing herself to be open and vulnerable with Jay.

She closes her eyes again and moves closer to his warm body. Lying here like this, she can easily imagine the rest of their lives. The idea doesn't scare her as much as she thought it would.