Based on a prompt, the link is posted on my profile, or you can use this: bilesandthesourwolfDOTtumblrDOTcom /post/71604792010/be-the-person-they-fear-you-are-like-can-this

HUGE thank you to my beta Twilight 684!

Warnings: work in progress, AU, not canon-compliant, mentions of violence, rated M for later chapters - PM me if you have any specific questions/concerns

Disclaimer: I do not own Teen Wolf and I am making no profit from this writing.

Chapter 1: Reporting Missing

Stiles Stilinski was not an eavesdropper. He knew how to mind his own business. The thing was, he considered a lot of things to be his business. For instance, this building was his business. So anything that happened in this building was his business. It was just logical that he should listen in to the conversation in his partner Lydia Martin's office. If it was really private, she would have remembered to close the door. Leaving the door ajar was practically an invitation, how could he refuse?

"Ms. Hale –" she was saying. Stiles stiffened in alarm. No, he told himself, it's a common name, it could be anyone. Just because she was talking to someone with the last name Hale, didn't mean it was a Hale he knew. Besides, Lydia would have told him, right?

"Look, I'm sorry, but –"

"I realize that, Ms. Hale, but our policy is very clear –"

"I will not put Stiles on the phone," she hissed, "He's been through enough –"

He pushed the door lightly, pleased when Lydia looked up in surprise, her lips forming a soft oh of dismay. Good. He didn't like to think of himself as petty, but he didn't need her to protect him, he could handle a phone call.

"Give me the phone," he said, giving her his best poker face. She pursed her lips for a moment, then sighed and handed it over.

"Stilinski speaking," he said into the phone.

"Stiles! Thank God! It's Cora, Derek is missing…" she went on for a minute, but Stiles wasn't listening. He was stuck on those three words, Derek is missing. Derek Hale.

Derek Hale, who studied architecture and secretly loved Batman. Derek Hale, who had ridiculous bunny teeth and a bright, genuine smile. Derek Hale, who was afraid of his father's badge and gun, but stayed for dinner anyway because Stiles asked him to. Derek Hale, who said Stiles could do anything he put his mind to. Derek Hale, who he had wanted to spend the rest of his life with. Derek Hale, who had said I love you and goodbye in the same breath.

Lydia gently pried the phone out of his fingers, drawing him out of his trance. Cora was still talking.

"And he's all I have left, and I know you two have history, but –"

"Ms. Hale," Lydia interrupted, reclaiming the phone, "Come to the office tonight…Yes, just come to the back door when you get here, our security guard will let you in."

Their "security guard" was actually just Jackson, Lydia's boyfriend who always came over on nights she was on call. He said he was protecting her, but Stiles had seen them through the window more than once – just last week, he was passed out in her lap watching The Notebook. It was pathetic.

Lydia set the phone back down in its cradle and opened her desk drawer, flipping through the files before pulling out a thin manila folder with HALE, DEREK written on the tab in black marker.

"Maybe it'll be good for you to talk to Cora," she suggested as she opened the folder and scanned the page with her index finger, "It might give you some closure."

Closure. Right. Moving on. He had tried – with Heather, Malia, and most recently, Kyle – but he just kept comparing them to Derek. He had been so in love, and he thought Derek loved him back. That was hard to just let go, even after nearly three years.

"Lyds?" he asked quietly.

"Mmm?" she looked up briefly. He swallowed.

"I want to read his file," he admitted. She didn't look happy about it, but she nodded. Tapping the page with her finger, she stood up and went to the bookshelf, pulling out a large black box from the bottom shelf.

"Okay," she huffed as she lifted it, "Everything you need to know about the case is in here."

He would make a joke about the extensive file, if the circumstances were different. But it was Derek, and nothing about this was funny. Derek had left him, and that hurt, but he still cared. He had been upset, yes – hell, he had been furious about the way Derek ended things – but he had never wished him harm. The thought of him in trouble, even now, made his hands shake.

"Thanks," he muttered as he accepted the box, "Have Jackson send her to my office when she gets here."

She nodded, "And Stiles? Remember, he pulls this crap all the time. Don't let your feelings get in the way."

"I know, Lyds," he didn't have the energy to argue with her. The anger had left him as soon as Cora had spoken those awful words: Derek is missing. Defending his ability to separate work from his personal life just didn't seem important, faced with the possibility of Derek in danger.

He set the box down on the floor next to his desk and started looking through the folders. There were maybe a dozen folders that were obviously about Derek, labeled things like POLICE REPORTS, BASICS, PICTURES, and AFFILIATES. Then there was a divider, and more folders – HALE, CORA; HALE, LAURA; LAHEY, ISAAC.

He decided to start with Derek, it seemed like the most logical place. He pulled out the folder labeled PICTURES first, out of curiosity. And wow. That was possibly the most flattering mugshot Stiles had ever seen, and he had seen a lot of them in his time snooping through his dad's desk. (What could he say, he had always been destined to be a detective.) He checked the date: just over a month after they broke up. Interesting. Derek went from law-abiding citizen to…drunk and disorderly? He blinked, rubbed his eyes. Nope, it was still there. He tried to picture Derek as a drunkard. He couldn't do it, so he shook his head before flipping through the folder until he found the crime scene photos.

If you could even call it that. It looked like an average apartment, albeit a rather Spartan one. No furniture was overturned, there were no broken lamps, no haphazardly thrown laundry. The bed was even made. He closed the folder and set it aside before pulling out the file labeled POLICE REPORTS.

That was interesting: a 911 transcript.

Responder: 911, what's your emergency?

Caller: Hi, there's, um, there's a lot of yelling at my neighbor's house, I just, I'm a little worried, and I was hoping someone could check it out – I don't want to get involved.

Responder: What's your location?

At the bottom of the page was written in Lydia's careful script: officer sent to house – domestic dispute, no charges filed.

What was strange was that the next six pages were all 911 transcripts, and at the bottom of each page, she had written the same thing: domestic dispute, no charges filed. He couldn't imagine Derek – what, beating his girlfriend? Was that what they were suggesting? But it struck him as odd that the neighbors would keep calling if there was really nothing going on. Then again, maybe he just lived by a bunch of paranoid old people.

There was a knock on the doorframe. He looked up to see Cora Hale standing there. He thought about standing up to greet her, but it seemed ridiculous to put on airs with her. Cora had always been shrewd, she would see through any act.

"Cora," he smiled a little, and it wasn't hard. They had drifted apart after the break up, but things had never been hostile between them. Cora had been upset that they broke up and tried to convince Derek to call him. He never did, but Stiles appreciated the effort.

"Stiles," she replied carefully as she moved to sit in the chair across from his desk. Her relief when she had called earlier had been obvious, but now she had collected herself. It was reassuring, in a way, to know that some things hadn't changed. No matter what, Cora was cool as a cucumber.

"I don't want to waste your time," he said, deciding to skip the pleasantries, "But honestly, I don't see anything here. Are you sure he's not just…"

He trailed off. He didn't want to talk about the break up, even abstractly, but this was what Derek did. Something happened, he ran. He couldn't handle dealing with his problems like a mature adult. He had never been able to, not since high school. He had reacted to Paige's death by acting out – running away from home, disappearing for almost a week. (Stiles still didn't understand why his parents weren't more concerned at the time, but Tahlia had only sighed and said he would come back when he was ready.) After the fire, he had been a wreck. It was months before he was discharged from the hospital. They hadn't been dating, hadn't even really known each other at the time, but Stiles had heard all about it – Derek had never been particularly open about that time in his life, and he hadn't wanted to push, but he had been the talk of the town for months after the fire. It was like everywhere Stiles went, everyone was whispering about the Hales. And then Laura happened, and he had gone off the deep end.

"I'm sure," Cora interrupted his thought process, narrowing her eyes, "He's my brother, he wouldn't just ignore me like this."

Stiles raised an eyebrow. Derek had ignored him for weeks after the break up, it wasn't much of a stretch to think he might be ignoring Cora for whatever reason. She frowned at him, pulling out her phone and pressing a few buttons.

"Cora, pick up the damn phone. I need you to –" there was crackling, then the call cut out. She gave Stiles a triumphant look. He shrugged. Okay, sure, he was willing to concede it was good that Derek had contacted her, and yes, he sounded stressed, but it didn't prove anything. Certainly not foul play.

"It was from a blocked number, not Derek's cell," she pointed out, which still meant absolutely nothing as far as Stiles was concerned, "He called me again last night."

"Cora," Derek sounded hoarse, and he coughed hard: a wet, sick sound, "Fuck, Cora, it's the fire. Laura got too close, that's why –"

"Aw, sweetie," that voice gave Stiles chills, "I really don't want to hurt you."

There was shuffling, Derek hissing something he couldn't make out, and a sharp crack before the message ended.

"Fuck," he hissed, "I'm gonna need to borrow your phone."

"Why?" Cora demanded.

"Do you want your brother back or not?" he snapped. He wasn't in the mood to deal with this bullshit. This case had just gone from runaway to kidnapping. It was a job for the police, even he could admit that. And he fully intended to report what was going on to his father later, but if Derek had been taken outside the county, he would be out of his jurisdiction. No way in Hell was he going to trust Derek's safety to some random gun-toting deputy.

She swallowed, looking hesitant, but finally nodded and passed the phone over.

"I need to make a call, don't move," he ordered, picking up his desk phone and dialing.

"What."

"Fuck you, Ethan, put Danny on the phone," he couldn't be bothered to make nice with Danny's boyfriend right now, "Tell him it's urgent."

"It's Stilinski."

There was some crackling as the phone was passed.

"Stiles, what's up?"

"Are you busy right now?"

"Uh, sort of. Why?"

"I need a favor."

It took another five minutes of guilt-tripping and blackmailing (and carefully evading who was involved), but Danny finally agreed to come over in an hour, "just so you'll shut up." Stiles was fine with that, he had never had a problem annoying people into doing things for him. He sarcastically thanked him (he would be worried if he sounded sincere, they weren't those kind of friends!) before hanging up the phone.

"Okay. Start from the beginning," he directed, waving a hand at Cora. She wrung her hands in her lap in an off-color show of anxiety.

"He changed, after Laura," she whispered, shaking her head slightly as if to clear her thoughts, "You saw how he was. He freaked. He dumped you, and –"

"Yeah, I know that part, thanks," he snapped. He didn't need a rehash of their break up, as if he hadn't replayed every moment in his head a thousand times over, thinking about every little thing he could have done differently. (If he had stayed a little longer, if he had held him just a little tighter, if he had told him how much he loved him just a little more often…) She nodded.

"Right, but you didn't see…you weren't there. He was obsessed with finding her killer."

Stiles could understand that. It was bad enough that his sister died, but Laura's murder had been horrific. She had been slashed into pieces and left scattered on the Hale's old property. Derek had been devastated, which shocked no one. Stiles tried, he tried so hard to help him, but Derek only pushed him away. It was a few weeks after Laura's death that they broke up.

Derek hadn't told him he was looking into the murder, but it didn't surprise him. He had suspected as much.

"A few months ago, Derek started acting weird – sneaking around, showing up late to work, getting into trouble. He got arrested for disturbing the peace and trespassing, twice. He's never so much as gotten a speeding ticket! He went off the radar for days at a time. He showed up to Uncle Peter's birthday drunk. He doesn't even drink!"

No, he didn't. Stiles remembered. He said he didn't like to feel out of control. Stiles had always wondered if there was a story there, but he didn't ask. He put it down to trauma; Derek had issues up the wazoo.

"So I called him out on it, and he said he was dating someone. He wouldn't tell me her name. He said it wasn't serious, but I know Derek, he doesn't do casual. And the way he talked about her, he said she was wonderful, and she made him feel alive again. He said he couldn't imagine being without her. Does that sound casual to you?" she demanded, but it was obviously rhetorical, "He said she was the most beautiful woman alive. But he was so evasive. She called his cell sometimes, and he'd always answer, but he'd go close himself in the bathroom or something so I couldn't hear. Then, all of a sudden, about two months ago, he stopped answering his phone. I called his boss and he said he quit weeks ago. I went to his apartment, and his car was gone. I tried the front door, but he changed the lock. So I broke in through the window – what, stop looking at me like that, it's not like he'd have had me arrested – and it looked like he hadn't been there in days, at least. There were dirty dishes in the sink, and rotting fruit on the counter. Derek's not a slob. He always kept his apartment clean, but it was gross. I kept calling him, he never answered. Then he called me and left that first message, in the middle of the night. And the one last night. That's all. I haven't heard anything else."

Stiles scratched his head.

"Do you know anything about the girlfriend?" he asked. She shook her head, "What about the fire? What does it have to do with Laura?"

She hesitated, pursing her lips thoughtfully for a moment, before finally answering, "You remember how your dad said it looked like a gang's work? Like a warning?"

He nodded. He didn't like to think about it too closely – he had insisted on going with Derek to identify the body, he thought his years of snooping around crime scenes would ensure he could handle it, but nothing could prepare him for the sight of beautiful Laura spread out on a metal table, her black hair spilled wild around her head and neck, her mouth frozen wide in what could only be described as horror, the lower half of her body missing. It had been days before Derek found the other half in the preserve, when he had called Stiles during class and been too distraught to say anything but his location and "I'm sorry, I'm sorry, just, please…" Stiles had ditched class immediately and stayed on the phone with him through the nearly hour long drive back to Beacon Hills, talking softly about derivatives and theorems and whispering "shhh, I'm right here, I'm on my way, I'm not leaving, Der" each time he heard a hitched sob on the other end of the line.

"We never knew what happened," Cora was explaining, "Laura never did anything to anyone. I know Derek had a few ideas, but he was so afraid…"

Stiles hadn't known that. Derek had been edgy in those weeks leading up to the break up, but he had always assumed it was grief, possibly his PTSD resurfacing. Derek had always been quick to hide his inadequacies (fear, anxiety, sadness) behind a wall of anger. He thought of all the times Derek had looked over his shoulder just a little too long, flinched just a little too violently when someone startled him, hovered just a little too closely for comfort. It had never occurred to Stiles that his sudden mood swings might be driven by fear, he had always just assumed it was Derek's way of coping with his sister's unexpected, and certainly horrific, death. It hadn't seemed fair to criticize his behavior when he was dealing with something so unimaginable.

"What kind of ideas?" he asked.

She shook her head, "I never knew; he never wanted to talk about it. He asked me not to look into it. It wasn't until last night that I realized he thought it was related to the fire."

She pointed to a folder labeled HALE FIRE. Stiles pulled it out and started flipping through it. There were newspaper cutouts, with headlines like, "Tragic fire kills nearly twenty", "Historic home lost in smoke", and "Blaze leaves eighteen dead and three severely injured". Stiles remembered how his father had come home smelling of smoke and ash that night.

"They ruled that it was electrical failure, right?" he asked, knowing the answer but needing to confirm it.

Cora nodded slightly, "Derek always suspected it was arson. It was too coincidental – it was our grandmother's 92nd birthday, it was a big party. I remember everyone was screaming, and Dad said, 'it's okay, don't panic.' But the door was locked. Derek broke the window, but I was the only one small enough to fit. I remember he pushed me out and told me to run. I ran to the neighbor's house, and they called 911. I could hear my mother screaming. When they finally put out the blaze…they let me ride with Derek, he flat-lined. When he woke up, he said…he said the last thing he heard was a woman giggling. At first I thought he was hallucinating, but…"

"But they found footprints," Stiles said it for her, because he remembered. He remembered his father saying there was evidence of arson, and what kind of monster would do that?

A madwoman would, he thought. There hadn't been enough to look for a killer (because that's what she was, a killer, after she murdered eighteen people in cold blood, and left another three for dead). And there was evidence pointing to an electrical failure, they had called in the fire chief and an electrician to look it over and they had deduced that an electrical failure was the most likely explanation. Stiles remembered his father had been furious, but they had insisted, "this kind of thing just doesn't happen in Beacon Hills, John – it was a tragic accident, but that's all." With three of the five remaining Hales in critical condition at Beacon Hills Memorial Hospital, Cora too young to testify, and Laura overwhelmed (suddenly having to take custody of her three younger siblings – two hospitalized – and decide whether to pull the plug on her uncle), there hadn't been anyone to push for a more thorough investigation. Tahlia Hale was a respected lawyer, and Stiles knew she would have gotten their arsonist locked up for life, but she hadn't survived the fire. With her gone, the only one physically able and old enough to take her place was Laura, and she couldn't focus on revenge when she had two younger brothers on death's door. It was all she could do to make funeral arrangements for the dead, and even that had been a tremendous undertaking, ultimately arranging nineteen (after one brother succumbed to his injuries) and finding plots where they could bury all of the bodies (what was left of them) side by side.

"You'll help him, right?" Cora was saying, bringing him back to where he was. He blinked, startled from his reverie, realizing she wanted an answer. It came to him immediately, there was only one answer he could give her. He couldn't live with any other answer.

They may have broken up, but he still loved him. It wasn't even about winning him back. Stiles could never explain why he wanted to open a private detective agency with Lydia, but he thought it might have something to do with this – the need to protect people from this, from not knowing what had happened, from being left in the dark. A small part of him knew it wasn't only about Cora's suffering though, it was about Derek, who had been through enough and didn't deserve to have his remaining family ripped from him, not to mention his freedom, if Stiles was correct in his assumptions.

"I'll bring him home, Cora."

Reviews are love! I'm also in the midst of writing Lights Will Guide You Home, so I'm not sure how quickly this will be updated, but I'll do my best. This is my first Sterek story and I'm super excited. :D