The ring of his desk phone drew Cas Novak out of the file he was rifling through, and he set it aside to pick up the hefty receiver. "Yes?"

Tris, his new, somewhat compulsive secretary was on the other end. "He's waiting in Interrogation Room C."

His eyes flicked over to the file open on his desk, the barest of smirks tugging at his lips. "How long did that take?"

"He's chained to the table, if that's what you mean, sir. He knocked out two of his handlers on the way in." She had probably already written up the report.

The smirk widened into a full-on grin. "Let the supervising officer know I'll be right in."

He set the receiver down and picked up the thick file again, eyes tracing the name printed below the male-model-esque mugshots of the high-profile serial killer.

Dean Winchester.

Cas had been tracking this man for months, always a few steps behind the slew of mutilated bodies he left in his wake. The file in his hands was weighed down with crime scene photographs, psychological analyses, and the transcripts of the scant video footage they'd had of him before his capture. There was a grand total of forty-two crime scene reports written in Cas' quick, decisive language. Thirty-eight weeks of Cas' life.

Normally, cases like this didn't get solved so quickly. Killers could be on the loose for years, decades. But Cas had solved it using the same factor that had taken him from the lowest ranks of the FBI to being Supervisory Special Agent of Washington, DC in the time it'd take an average man to do half of that—he was smart.

For some reason, he just knew how killers ticked—which was why he was going into the interrogation fully convinced that he knew anything and everything about Dean Winchester.

He held the folder close to his side and stood, brushing out the wrinkles in his impeccable navy blue suit. He couldn't help giving himself a brief once-over in the glossy screen of his monitor. There was no way he was appearing in front of Dean looking like just any agent from any office across the country. He was going to leave an impression. He was the man who was going to put this man away.

It didn't hurt that the amount of publicity this case was giving him was making his superiors hint at promotion. If he worked the Winchester case right, he could make his entire career off of it.

Finally satisfied with his appearance, Cas nodded to himself and strode across his office and into the hall. Tris' blonde head peeked up from behind her cubicle, and she rose to greet him, carrying a cup of coffee and a ruler. Cas never personally cared much for how his coffee was prepared, but knowing his secretary, she had heated it to precisely two-hundred degrees Fahrenheit, brewing temperature, with two packets of cream, no sugar.

She handed him the cup, the porcelain surface scalding to the touch. Cas' fingers shifted on the handle so his knuckles didn't brush the side and took the ruler from her with his free hand.

"Will that be all, Mr. Novak?" she asked. Cas took in her pristine attire, from the perfectly ironed blouse to the lint-free skirt. He had never had the time for romantic relationships, but perhaps if he ever did find the need to enter into one, she might be a viable option.

"Yes, thank you, Tris," he replied, shaking the thought off. It didn't have a lot of appeal, for some reason.

She nodded, her high ponytail bobbing once, before she returned to her desk and kept typing. Cas watched her for a moment, then continued down the hall. All about him, there was the everyday bustle of the workplace, copiers humming, keyboards clacking, agents talking, but Cas knew that this day was very, very different.

Today was the day he'd finally meet his competitor, his tormentor, and in a way, his friend. Dean Winchester had been his life for more than six months. He knew the way Dean liked his coffee – black, if he drank it at all – and that his favorite order was a double bacon cheeseburger. He knew that he had experienced abusive trauma in his youth, causing him to lash out at those around him – specifically, happy couples. He knew that Dean was likely bisexual. He knew that the killings had started right around the time his younger brother had died, and he'd just cracked.

Oh yes, he knew a lot about Dean Winchester. This interrogation was just going to prove it.

The trip down the hallway seemed to take an eternity. When he'd finally figured out where Dean would be next, lead in an armed squad to take care of him, he had never expected to take him alive. It was just the kind of man Dean Winchester was—he wouldn't come in without a fight. But for some reason, when he saw Cas, he just grinned and held up his hands. He hadn't spoken a word.

Cas blinked, coming out of the memory and returning to the present, where he was currently standing in front of the two agents guarding the door to Interrogation Room C. He gestured to the door next to it with his head, asking, "Is Special Agent Balthazar behind the glass?"

"Yes, Special Agent," one of them said. They were probably new agents, just out of Quantico. He didn't know their names.

He nodded, taking a sip of his strong coffee, and instead of walking into the interrogation room to confront Dean Winchester, he stepped to the side and went into the room behind the one-way glass, where his good friend Agent Balthazar was watching Dean through the glass. He was leaning over the main desk, flipping through a copy of the file that Cas had tucked under his arm, while absently making sure the recording equipment was fully functional. His flamboyant orange and green tie dragged against the pages. That was the kind of agent he was; almost the functional opposite of Cas. He loved to test the rules, push the envelope, while still barely within the FBI's regulations. That was why Cas could see mismatched patterned socks peeking out from beneath the hems of his black suit.

When Cas entered, he looked up at him, tossing him a cheerful smile. "Well, this is it, isn't it?"

Cas nodded in agreement and moved over to stand beside him, looking through the tinted glass at the man hunched over in one of the two metal chairs. His dull green jacket hid a built physique, and his honeyed brown hair stood up in unwashed spikes on top of his head. But Cas knew the appearance was an illusion. He was no ordinary inmate.

He sucked in a deep breath and allowed a relieved smile onto his face. "I can't believe we did it, Balthazar."

"You say 'we' like I had a big part in this. Don't drag me in, Cas. This was all you." He clapped his hand solidly on Cas' shoulder and chuckled. "Congratulations."

"Thank you," Cas answered. He took another sip of his coffee, about to ask Balthazar if anything had happened while Dean had been waiting, when the man in the chair stirred and lifted his head. The chains binding his handcuffs to the loop in the table clattered together.

His hard green eyes bore through the mirrored glass, like he could see straight through it, straight to Cas. "Hey," he said loudly. "You gonna interrogate me, or am I just going to sit here until I rot?"

Cas held in a shiver at his deep voice. This was it. Without looking at Balthazar, he made the half-hearted offer, "You could come in with me if you wan—"

Balthazar let out a laugh. "Yeah, right. Break his ass, Cas. I'll be here."

He handed Cas a clear plastic earpiece so he could speak to him while Cas was interrogating Dean. Knowing Balthazar, he probably wouldn't say anything. He knew how long Cas had anticipated this moment, and he wasn't about to bust in and take it away from him.

Cas took the earpiece all the same and placed it in his ear. He readjusted the file in his grasp, tucking the ruler in among the papers, then picked up his coffee again and let out a heavy breath. If he'd been a less experienced agent, he might have felt the need to shake out his nerves. Pulling in more than ten high-profile killers over the years had taught him that it was better to go in nervous; it gave him an edge.

"Wish me luck," he said, then stepped back into the hallway, letting the door fall shut behind him. He walked over to the armed guards and waved them aside so he could open the door himself. The handle was cold to the touch.

He pushed open the door and stepped into the quiet interrogation room, then shut the door carefully behind him. Dean's eyes followed him as he travelled across the room to set his things on the table opposite Dean. Cas pulled out his chair, but he didn't sit.

"Dean Winchester."

"Castiel Novak." The words twisted in Dean's mouth, his lips curling up in a wry smile. His rugged good looks were unfitting for such a criminal mastermind.

Cas raised a single eyebrow at the killer. "You know my name."

"I read the paper on occasion," Dean replied noncommittally, leaning back in his seat. The chains shifted again, the cuffs hiking up his wrists to reveal more of his tan skin. Cas took in his entire appearance, from the sculpted jaw to the gray tee under his jacket to the worn-looking blue jeans that just brushed the tops of his dark boots.

Finally, Cas took a seat, maintaining a perfect posture. He slid his file folder closer to where he was sitting and flipped it open to pull out the innocuous yellow ruler. He held it up for Dean to see, and the killer gave him a suggestive look.

"Look, Cas, I'm all for kink, but not with the camera up there. I don't want people watching," he said, looking pointedly at the security camera in the corner of the ceiling recording the encounter. "But maybe later, yeah?"

Cas licked his lips and started into what he did with every serial killer he brought in. "This ruler represents your life."

"I appreciate the visual aid, Cas, but I don't care," Dean interrupted.

Ignoring his comment, Cas pointed to the four inch mark on the ruler. "This is where you are now."

"I'm way bigger than that, I can tell you."

Cas felt a flush of heat rise in his chest. Again with the suggestive remarks. This wasn't in the profile. All signs pointed to Dean having an aggressively asexual view to the world to protect his conscious self from his subconscious desires, and here he was, teasing Cas, working him up. Cas swallowed tightly and decided to do something different for once.

He took in a deep breath, then snapped the end of the ruler off, tossing the four inch piece onto the table in front of Dean. The killer watched with an amused expression, eyebrows hiked up towards his hairline. Cas barely refrained from raising his voice as he continued, "And that's all the life you're going to have. Because the rest is mine."

"Oh, you want to be on top, do you?" Dean smirked, then he leaned forward, his green eyes prismatic beneath the harsh fluorescent lights. "I'm sorry, I thought I made it pretty clear that that's not how it works."

Instead of backing down and maintaining the professional façade, Cas felt his lip curl. He inched forward too, fixing a hard stare on Dean, brandishing the ruler. "It's going to work however I want it to work. I've got your file. I've got your victims. I've got your footage. There's no way you're not getting convicted. And I will use you, just like you used your victims to displace your sexual anger, to get ahead, because you're my bitch now."

The moment he finished speaking, he knew he'd made a mistake. Instead of shutting down Dean, which, in all honesty, he hadn't expected to happen, it made the killer's eyes burn brighter. His full lips parted, allowing the words, "Then prove it, Cas," to escape.

Cas didn't know what he would have done next if he hadn't heard Balthazar's tinny voice in his ear saying, "Cas? You need backup?"

Slowly, with measured movements, Cas reclined in his seat, rejecting his prior uprightness for a more relaxed position. He glanced over his shoulder at the mirrored glass behind him and gave a sharp jerk of his head. No. He was going to take on Dean himself. He had the right.

Cas pulled his folder closer to him, tucking the end of his ruler into it, then flipped to a few pages in: the first crime scene photos. They showed a cream-colored living room, the walls stained with blood and the floor strewn with the remnants of two victims: a man and a woman in their early thirties. The heads were found later, buried beneath the rose bushes on their front lawn.

"Your first kill was February 3rd," Cas stated. He watched Dean's face, waiting for him to contradict him, but the only thing the killer did was smile wider. Cas had expected that kind of a reaction: serial killers did what they did out of narcissism. If they didn't get caught, then what would the point of it all have been? They had to prove they were smarter. That they were better.

Cas' lips tightened before he forced them into a grin. "You left very few clues for the forensics team to pick up. Very clean."

"I'm only dirty in bed," Dean said, attempting to lean back further but finding that his bound hands didn't allow it. He shifted seamlessly forward so that his forearms rested against the silvered metal table. "But you're telling me things I already know you know, Cas. Make it interesting."

Cas' eyes travelled over Dean's taunting face. Then he flipped a few pages over to the preliminary psychological report on the man in front of him. He merely did it for effect; he had practically memorized the pages-long document. "Your father abused you as a child, didn't he, Dean? Sexually."

Dean jaw worked for a second before the corner of his lips turned up in a smirk. An odd pang shot through Cas' chest at the expression. "Wow, that took a lot of figuring out, didn't it? To be honest, I'm kind of sad he died of a heart attack before I finally grew old enough to stick it to him. He would've been my first kill."

This was not going the way Cas had wanted it to. Serial killers were typically very open about their crimes, but Dean was steering the conversation. Maybe he was right about being on top—

"Now, you, Castiel," Dean continued, interrupting Cas' strange interlude in . . . whatever his thoughts had started turning to. Dean's chains rattled as he dragged his chair closer. "You are interesting."

"You don't know anything about me," Cas answered, feeling his confidence waver momentarily.

Dean snorted a laugh. "Au contraire, Special Agent. I know a lot about you. For example, I know that your father was one of the most powerful people in the FBI, right before he disappeared off the face of the Earth. No phone calls, no emails, no nothing. Your father ditched you, and you still haven't gotten over it. You're still looking for him. And you're attacking me for daddy issues?"

Cas' fists clenched. He was about to jump out of his seat and for all intents and purposes tackle Dean Winchester to the ground, damning the consequences, when Balthazar said, "Breathe, Cas. Take it easy. He's just trying to get to you."

Cas knew that, too, somewhere in the back of his head. He knew what game Dean was playing at. But for some reason, it was so much more effective coming from Dean than any other killer off the street. He needed to think, but he couldn't think with Balthazar in his head.

Without hesitation, he pulled the earpiece out and set it on the table. Balthazar's voice came out as a crackle of static, then there was the distinctive concussive sound of a door slamming. The earpiece fell silent. Cas' eyes slid from it to Dean, who contemplated the clear plastic.

"So we're alone now, are we?" Dean asked, his voice dropping a notch, again sending that strange sensation rattling through Cas' chest.

"You're still being recorded, Dean," Cas said, tugging his chair forward with his toes so he could put his elbows on the table. "So don't do anything I wouldn't do."

Shit, what? He was going to say don't try anything, but something happened to the words on the way to his mouth. He couldn't show that, though, so he stuck it out, raising an eyebrow at his now slightly slack-jawed companion.

It took less than a second for Dean to regain his composure. He cocked his head and sneered. "No, you're right. I wouldn't want to make you use force, would I?"

The comment needled Cas more than it should have. He slid Dean's file to the side and hissed through his teeth, "Didn't I make it clear earlier? I spent over six months chasing you, and now that I've got you, I'll treat you however I want because I have goddamn earned it."

Dean's face inched closer, and his lip curled just enough to make the hairs on the back of Cas' neck stand on end. "Well, well, well. I was wrong. Maybe you'd do well on top."

Before Cas could filter out the literal meaning from Dean's innuendo, he snapped back, "'Maybe'? I am on top, Dean."

"Then prove it," Dean murmured, his eyes tracing Cas' features with an unreadable expression on his face. "There's no one watching."

Instead of meeting Dean's iridescent green gaze, Cas dropped his eyes to the killer's handcuffed wrists and the hands that splayed out on the table in front of him. Long, scarred fingers, but he knew they were strong—some of the victims still had hand-shaped bruises on their cold bodies, prints that matched those before him. A flicker of an image passed through Cas' head, the imagined sensation of those hands on his skin—

All of a sudden, Dean heaved a sigh and sat back in his seat, taking the dangerous heat and masculine aura with him. Cas felt an emptiness in the pit of his stomach as he still sat frozen in place.

"Of course not," Dean muttered. "Because you're a good little soldier, aren't you, Cas?"

Between one blink and the next, Cas' hand shot out and grabbed Dean by the shirt collar. Cas didn't know what he was doing, but it didn't feel wrong, so he didn't stop. He tugged Dean forward and up, rising from his seat. The killer was taller than he was, but that didn't bother Cas.

"Soldier I may be, but at the moment, I'm the soldier with the gun in your mouth and the finger on the trigger, so I'd shut up if I were you," Cas growled.

Dean's chest rose and fell faster, lips parting in a teasing grin. "Make me."