Author's Note: Sorry for the delay. I never intended to go this long between updates, but figuring out how to handle this crossover case took longer than I planned, and I got a little distracted by a couple of other fics.

This chapter begins a two or three chapter arc to address the first Greg Yates encounter. Any familiar dialogue was lovingly borrowed from CPD 2x20.

Thanks for all of the love!

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Hank had been surprised to see a video call coming through his computer. Since Olivia's visit to Chicago after he was shot, they'd made regular video calls a necessary part of their friendship. However, this call was coming much earlier than their routine chats.

He was also surprised when, during their call, she questioned him about the case he and the unit were currently working on, a nurse who'd been assaulted and left in a burning building, her body badly burned. As he relayed the limited information he had at that point, Olivia recognized the details of the case, reminiscent of a case she'd worked years ago. A short few hours later, Olivia was on a plane to Chicago, and now, Hank was watching her walking toward him where he was waiting at the firehouse, and he was surprised when he suddenly realized how much he'd missed her.

Olivia looked beautiful as she walked into Chief Boden's office. Her hair seemed darker than he'd remembered, and her all black ensemble, while gorgeous, still commanded respect as much as it commanded attention. Perched atop her head were her reading glasses, and although he hadn't seen her wear them, he knew the sight would probably send him to his knees.

Hank introduced her to Boden and immediately began filling her in on the latest developments in the case, hoping to distract himself with work before Olivia's presence distracted him from his work.

The case was gruesome, sobering him even with the close proximity of Olivia. The victim had experienced a horrific trauma, one of the worst Hank had ever seen, and he was determined that with Olivia's help, they'd get her justice, no matter what.

After discussing the case a little further with Boden, Olivia requested to go to the hospital, hoping to meet with the victim and get as much information as the girl could remember. Hank immediately offered to drive, and after gathering what they needed from the firehouse, they were on their way.

As Hank drove, Olivia placed a video call back home, spending a few minutes speaking to her son. He couldn't hold back a smile listening to her sweet "mom voice" as she talked to the little boy. Noah was young enough that he only babbled, occasionally slipping a "Mama" into the conversation, and Hank loved seeing her like this.

When the call was over, Hank drew her attention with a quiet, "You miss him already, don't you?"

"I do," Olivia answered. "I know I just left, but being away from him is hard."

"You're a good mom, Benson. The kid is lucky to have you."

Olivia finally looked over at him and smiled. "Thanks Hank. I'm a mess, but I love him like I gave birth to him."

Hank reached over, gently placing his hand on top of Olivia's. Their fingers didn't intertwine, but he felt Olivia relax into his touch, and it made him smile, just a little.

"I'm glad you're here," he said softly, and he felt Olivia's fingers separate, just a little, just enough for his to slip in between.

Olivia's eyes quickly flitted over to his. "I'm glad to be here too, Hank."

They were silent the rest of the drive to the hospital. When they arrived, before Olivia could open her door, Hank squeezed her hand, drawing her attention back to him.

"I know this case is difficult for you, knowing the offender could very well be someone from your past, but…" He stopped, his other hand reaching across the console to rest gently against Olivia's cheek. "I've missed seeing your face."

Although the look in her eyes was still haunted, as she was no doubt still lost in thought about the case, a small smile crossed her face as she leaned into his touch and whispered, "I've missed you too."

His thumb softly brushed her cheek before his hands reluctantly returned to his side of the car. "Let's hit it."

Upon stepping out of the car, both Hank and Olivia fell into Sergeant mode, determined to devote their attention to the latest victim, who was just inside, just barely hanging on.

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Olivia leaned against the hospital wall, her mind racing as she was bombarded with memories from the past case that had far too many similarities to the case in front of her right now. The new victim, Victoria, was a nurse like the previous, shared similar physical characteristics, and was raped and burned. The green nail polish was one of the biggest similarities, and Olivia felt nauseous thinking about working this case. But she felt a responsibility to figure out exactly what was going on and confirm what she'd feared most.

Her thoughts also drifted to Elliot. They'd worked the New York City case together all those years ago, and a part of her wanted to call him, pick his brain about what he remembered from their work together. Surely he'd know what to do, wouldn't he?

Hank returned from the hospital cafeteria, a cup of tea for her and coffee for himself. She was glad that if she couldn't have Elliot by her side for this case, at least Hank was with her. They'd previously worked so well together, and their deepening relationship, whatever they were calling it at the moment, could only help.

When the Victoria's doctor allowed them into her room, just briefly to ask a few necessary questions, Olivia's heart broke all over again. Nearly her entire body was bandaged and she could barely breathe, and Olivia could tell she was in excruciating pain. While she and Hank were questioning her, Victoria coded, and they were rushed out of the room. Olivia leaned against the wall, her eyes closed as she fought flashbacks from her own experience until Hank stepped in front of her, taking her hand and blocking her from view of anyone else in the hall.

"What do you need, Olivia?"

She shook her head, pressing her hand against her chest. "I'm fine," she choked out.

"No, you're not," Hank pressed. "But I'm here when you're ready to talk about it. Let's get to the district and see what my team has figured out so far."

Olivia nodded, took a deep breath, and pushed herself off of the wall to follow Hank down the stairs.

When they reached Hank's truck, before pulling out of the parking lot, Hank asked, "Do you want me to take you to your hotel instead of the district? It's late, and you've had a long day. I can work with my unit for awhile while you get some sleep?"

Although the offer was nice and she was exhausted, she felt she owed it to Victoria and all of the other victims to keep going, to keep fighting. Shaking her head, Olivia answered, "I need to keep working. Let's go see what your guys have found out."

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It seemed like with every passing moment, the case was getting worse. Not too long after they met up with Hank's unit at the district, they received word that their victim succumbed to her injuries. It broke Olivia's heart that someone she and Elliot tried to find all those years ago was still hurting people, and Olivia was determined more than ever to catch the person responsible for such destruction.

They worked through the night, and the next morning, while video chatting with her squad, Hank invited Amaro and Fin out to Chicago to help them there, while Carisi and Rollins worked hard from their own precinct. As the hours went on, Olivia found herself becoming more and more discouraged when the dots finally began connecting. Sadly the information began pointing toward the brother of one of Hank's detectives, and Olivia wasn't sure what she was going to do.

After taking some time to check into a hotel, shower, and meet her detectives for a quick dinner, Olivia texted Hank, asking him to meet her for a drink. She needed to let him know what she'd found out about Jay's brother, and even though she didn't need his permission to question Will Halstead, she respected Hank enough that she needed to let him know where their case was headed, knowing it would put his unit in a difficult situation.

They agreed that Hank would think about it and let her know how to move forward. When their drinks were finished, Hank reached across the table, his free hand landing on top of Olivia's. Very gently, his thumb traced hers soothingly, and Olivia found herself relaxing a little. His touch combined with the drinks had her slowly lowering the professional boundaries, and she flipped her hand over, allowing her fingers to tangle with his.

"Drive me to my hotel?" she asked, a small smile on her face.

Hank hesitated, and Olivia felt her stomach drop when he didn't immediately reply. Was he rejecting her? Even though they'd agreed only to be friends, he'd never turned her down before, and she felt a little embarrassed.

"Olivia," he started.

She jerked her hand away from his as she said, "No, it's ok. I shouldn't have said anything. I'm fine."

"Olivia," Hank tried again.

"I gotta go. I'll see you tomorrow," she said, reaching for her bag and starting toward the door.

Before she could get more than two steps away, Hank's hands reached for her, turning her back around to face him. One of his hands immediately cradled her cheek, and she felt herself leaning into his touch.

"I wasn't saying no, Olivia. I was just going to say we should probably catch a cab instead."

Olivia breathed a sigh of relief and reached for his hand. "Let's get out of here then." Hank smiled at her, threw a few bills on the table, and they were on their way.

When they arrived to her hotel, as soon as they were inside her room, Olivia reached for him. Hank pulled her into his arms, tucking her safely against him, but as she reached for the buttons on his shirt, his hand reached up to stop hers.

"Not tonight, Olivia," he said quietly, his hands running up and down her back. "It's been a long couple of days, and we're both exhausted and frustrated with this case, and as much as I want more, what we really need tonight is sleep. Go get changed, and let me hold you. I have a feeling we'll both sleep better next to each other. Ok?"

Olivia held his gaze for a few moments, until she realized he was serious. He wanted her just as much as she wanted him, but he was willing to put aside their desires and do what was best, at least for tonight. She missed this, the way he took care of her, the way he knew what she needed without her ever having to ask. He kissed her softly as he released her, and she gave him a small smile as she whispered, "Ok," before gathering her sleep clothes.

When she was changed, Hank was waiting for her in her bed. He threw the covers back and said, "Get over here, Benson."

She climbed in next to him and immediately curled up in his arms, finally relaxing and letting the stress of the day flow out of her. Hank was right; she badly needed sleep, and his arms were exactly where she wanted that to happen.

Before she could completely take her mind off of the case, she had to ask one question. "Is Halstead going to hate you for this?" Olivia asked.

Hank shrugged, seemingly unconcerned. "He'll get mad, but he'll get over it. We have to do what we have to do to get this case solved. If Will is innocent, we'll figure it out, and then we can move on. If he's guilty, we'll have the evidence to prove it."

He pressed his lips against hers before pressing them against her forehead. "Turn that brain off for the night and get some sleep, Olivia. Everything will still be there tomorrow."

"You turn yours off too, Hank."

He kissed her one last time. "Will do, Benson."

She snuggled into his arms, and in just minutes, she was asleep.

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The next day, the conversation with Jay's brother went worse than Olivia imagined. Jay was angry with her, angry with Hank, and refused to let them question his brother. Will was open to having the conversation, insisting on his innocence and offering up information to prove it, but Jay rushed him out of the office, ending the casual interrogation right there.

"That went well," Olivia said dryly once Jay and Will were out of the room.

Hank shrugged, unbothered by confrontation as h closed the office door so they could talk freely. "Will's fine, and Jay will get over it."

Olivia sighed, settling on Hank's couch as she pulled out her phone, scrolling through emails and missed texts from her squad members back home, and after seeing what she was missing, she realized it was time for her to head back home. There was too much information there that needed her attention, and Amaro and Fin could handle what needed to be handled in Chicago.

She looked up at Hank and reluctantly gave him her news. "I've got to get back home, Hank."

His look of sadness followed a look of surprise, and it broke her heart a little. "Already? Olivia, there's a lot happening here. We need your help with this."

"I know, but Carisi and Rollins are being flooded with tips that need to be followed up on, so I need to go help them. I'll leave the guys here, but I need to get home. Noah's still not feeling one hundred percent, so he needs me too."

Hank's head dropped for a moment as he accepted her words. When he looked back up at her, the smile on his face showed his understanding, but his eyes showed he was still sad to let her go.

"I get it. Noah needs you, and your squad needs you, but you'll have to forgive me for being a little bit selfish because I'm not ready to let you go yet," he said with a smirk.

Olivia laughed, standing up to gather her things. "I'm sorry. I'm not ready to leave yet either, but duty and motherhood are calling for me." Unable to stop herself, she reached out and gently put her hand on his cheek. "I'm going to go to my hotel and pack up and book a flight. I'll let you know the plan, and I'll stop back by before I leave."

Hank nodded, covering her hand with his. "I'll hold it down here."

She felt tears beginning to form in her eyes, but she forced them back and gave him a small smile. "Ok."

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Hank hated watching Olivia walk out of his office. Their time together was far too short, and the case was far too stressful, and he wished they'd been able to have time together. Even the night they'd shared was mostly spent discussing the case, but he'd rather talk about the case with her in his arms than standing across the squad room.

He carried her suitcase down the stairs, slowly following along behind her, prolonging their goodbye as long as possible. When they reached the front doors, Olivia turned around to face him, and he had to clench his fists to keep from reaching for her. He missed her already.

"You sure you gotta go?" he asked, already knowing the answer, but holding onto a sliver of hope that maybe, just maybe, he could convince her to stay.

Olivia knew exactly what he was doing, and he was thankful she was strong enough for both of them. "You'll be in good hands with Fin and Amaro."

When she reached to take her suitcase from him, she had one final request. "Do me a favor? Play this one by the book? Please?"

As she began listing off her reasons, he cut her off with a simple answer, one he hoped she knew he truly meant. "You have my word."

She gave him one final beautiful smile. "You take care of yourself, Hank."

He couldn't reply, for fear he'd beg her to stay, embarrass himself in the middle of the district, so he simply nodded his head. The look on her face showed she knew what he was thinking, and a moment later, she was gone.

Hank stood at the doors for a little while longer, until he was able to tear himself away and accept that she was really gone. Saying goodbye to her was becoming harder and harder, and maybe it really was for the best that she was leaving so quickly. He needed to get his head back into the case, needed to get justice for these women.

Little did he know how just hours later, the case would change direction, hitting closer to home than he could've ever imagined.