Thin Blue Line.

This is the first volume of series and it's going to mention the Reagan family from Blue Bloods but they aren't going to be in this as much. And it's also going to kind of be tied into Paradise Undone and Under Suspicion which is going to be a Law Order SVU story and Dirt Bag which is a NCIS story and Things Nightmares are Made Of which is a Criminal Minds story. If you can't tell I love, love crime shows and I have spent the last week I have been sick binge watching and perfecting the storylines for them.

Also for this series, Jay and Erin were never together for long, and she still goes to New York with the FBI leaving Jay alone. I am going to try and follow along as much as I can with everything after season 3 of Chicago PD.

The first few chapters take place in the start of season 2.

Summary: Libby Reagan's life was in shambles, the only bright side was her being made detective. And now she and members of the Intelligence Unit are trying to catch a duo of serial killers.

Rated M for Mature.

Eventual Jay Halstead/OFC

One

Socialite Murders

"Oh, come on Reagan! You have been in Chicago for how long and you still aren't a Chicago fan?" Billy Arden asked his partner who shrugged her shoulders and moved the rickety wood rolling chair she was sitting in to side to side. "I am a New Yorker through and through what can I say?" Libby Reagan grinned, still moving the chair back and forth making it creak as she did. "Yeah but you live in Chicago now! You should adapt to being a Chicago fan! Black Hawks, White Sox, Cubs, Bears, Bulls" He argued pointing his finger at her. She shrugged her shoulders, he wasn't the first person that told her that and he wasn't going to be last but she found it fun to argue with him about it. And it passed the time on slow days like this. ""Yankees, Mets, Jets, Rangers and Knicks. And at least the Yankees have won a title in the last 100 years." Billy inhaled sharply as if she had slapped him, "You just had to bring that up didn't you?" His partner grinned almost gleefully as she nodded her head.

"Reagan! Arden! You are up!" Sargent Hardy said coming out of his office, "There is a murder south of Halstead." "Well aren't we lucky?" Libby said standing up and shrugging her well worn leather jacket on, "They didn't kick it up to intelligence." "Oh someone is still jealous." Billy muttered following her lead. "Not jealous, just annoyed. He dropped me like a hot potato as soon as Erin showed interest." Libby returned as she held the car keys out to him. "Didn't your brothers ever teach you not to date cops?" "Nah. They would rather have me date cops then date a firefighter." Billy laughed as he tossed the keys to the sedan up in the air and catching them quickly. There had been a month and half after she first moved to Chicago that she was hot and heavy with the Squad 3 leader. It was hot, heavy and quick. Something that didn't seem like Libby at all.

And then she was reintroduced to Jay Halstead, a brother of a friend that she had in New York, Will had told her that she that they would be just perfect for each other. And that turned out to be false. Especially when Jay dumped her for his partner Erin, Billy and Leslie Shay had to peel Libby off of the floor. It was not a pleasant experience.

"Besides, not having a boyfriend is liberating, it's like not shaving your legs or wearing a bra." She grinned as they walked down the staircase to the lobby stepping aside as several other detectives climbed the stairs, shooting Libby a weird look for her comment.

"You say that now then your sister will call you and you will have a freak out moment then you are going to be back where you started dating the first guy that you see." "Shut up Arden." He laughed, they both knew that he was right and he didn't want to be the one that to peel her off of the floor like he did when her ex husband left her. "Look I promise, I won't go dating the first guy I see if Erin starts in on me if you promise to layoff of the whole Jay thing." He groaned before he nodded his head once, "Fine."

"Hey Lib." Jay Halstead greeted as he and Antonio Dawson joined her on the sidewalk outside of the diner were the murder took place. "Antonio." Libby returned ignoring Jay's greeting completely. "What happened here?" the older detective asked. "A girl Amanda Shore, from Lincoln Park was assaulted and killed. The perp took her wallet and jewellery. The girl was 17, planning a senior trip to Europe with her best friends. And this guy killed her." She explained, "Arden is in there right now talking to them." "And why are you out here?" Jay asked. "Weak stomach." She returned. "Well we are here to help. Tell us what you want us to do."