Castiel takes this call outside. He's not entirely sure he's allowed to talk to a witness while outside, but who's gonna fire him? Michael? The guy practically begged him to get involved in this case in the first place.

"Hi, Sam," Castiel says.

"What can I help you with, Agent Novak?" Sam asks.

"You can call me Castiel," he says.

"Well, what can I help you with, Castiel?" Sam asks. "I'm afraid I've already told you everything about last night, but if you have any questions about, say, growing up with him or something, I can help with that one."

"Actually, I think I already know everything I would need to know about that," Castiel tells him. "I mean, I'm sure it was a little biased, given that it came from Dean himself, but he'd long since decided he didn't need to impress me anymore."

"'Anymore'?" Sam repeats. "What, were you guys friends? I thought you were the one that arrested him."

"I was," Castiel says. "But there's a little more to it than that."

"Oh?"

"I don't know how much Dean told you," Castiel says. "I know he has a tendency to run his mouth about things he shouldn't, that he craves some type of connection and he will keep talking and he will keep fighting until he gets it."

"Oh, I don't know about that," Sam says uncomfortably. "I mean, maybe he'd changed in the last 12 years, but at least growing up, he wasn't the most social person."

"That's not entirely what I meant," Castiel says. "Dean and I go way back — 12 years back, to be precise. Those first five years, I wanted to find him and I wanted him off the streets, and I may have been secretly hoping I'd get the chance to pull my weapon to do so. Then he decided that he wanted to be my friend, and he would leave a phone number in blood at every single crime scene just to get my attention."

"Well, that is certainly very... creepy..." Sam says. "He didn't tell me that, if that's where you're going with. He just mentioned your name. He said he'd hoped we met. I didn't quite get it at the time, but this would explain it."

"Yes, it would, but that's not the point I'm making," Castiel says. "I have always and I will always hate Dean. I would expect you feel the same."

"Of course," Sam says without hesitation. "He's a serial killer. The sooner he's off the streets, the better. That's why I called. That's why I'm talking to you right now."

"Right, right, but you called this morning," Castiel says. "You called hours after he'd left — long enough for him to leave the state, and we'd never know where to look for him."

"I told you, I was —"

"You were processing it, I know," Castiel says. "That's the official story. That's the one going on the record. This conversation, as soon as it ends, it never happened. So you can tell me, or I can tell you, either one works, that you processed it the minute you saw him standing in the doorway. You knew you could shoot him. You're a lawyer; you know you had the grounds. You knew you could send him away and call the cops right after you closed the door, and he'd never know. But you waited, what, eight hours?"

"I was in shock," Sam says. "A serial killer was standing in my doorway. My wife and my kids were upstairs —"

"And he wouldn't have hurt them," Castiel says. "He has no concept of the value of human life, but he wouldn't have hurt them because he knew you wouldn't want him too. I think you knew that they were never in danger — that as uncomfortable as it made you that he was here, he was never going to hurt you or your family."

"What are you saying?" Sam asks.

"I think you let him escape."

"That's ridiculous," Sam says. "He's a serial killer. Childhood aside, I'm not going to let a serial killer —"

"I said the same damn thing seven years ago," Castiel tells him. "That he was a killer, and that I wasn't going to play nice. But there's something about seeing him in person that makes that so much harder than it needs to be, don't you think?"

"I don't know what you're talking about," Sam says, his voice flat. He's lying; that much is obvious. It's comforting, in a way. It wasn't just Castiel. This really is the effect that Dean has on people.

"The only reason I caught Dean was because he let me," Castiel tells him. "He grabbed me, and he let me live. The only reason he made it out alive is because I let him. I had every right to shoot him, and I didn't even reach for my gun. Does this sound like a familiar scenario?"

Sam sighs. "Yeah, that just about sums it up."

He knew it. He knew that was how it went down.

"I want you to remember this feeling," Castiel says. "I want you to remember how pissed you are at yourself for letting him escape."

"I didn't —"

"Because he will be back," Castiel continues evenly. "It might be tomorrow, it might be 20 years from now, but he will be back because he does not know how to leave well enough alone. And when he does come back, you can let him talk. You can let him talk all day. But you need to remember how you feel right now, and realize that you will feel just like this if you let him get away again.

"So, when Dean inevitably comes back, you have two choices. You can either let him leave and then call the cops, or you can shoot him on the spot. But you can't let him talk you into giving him a head start. It doesn't matter what he says or how he tries to convince you — or even how he accidentally convinces you. You can't let him get another head start."

"If you're accusing me of something, I'd appreciate it if you'd stop being around the bush," Sam says.

"If I were trying to accuse you of something, I would have had Tran and Harvelle do it, given that they could actually stand in front of you right now," Castiel says. "I'm just trying to warn you. I know you let Dean go on purpose. I can't prove it, and even if I could, I wouldn't pursue it. You can pretend you didn't if it makes you feel better, but this call is off-the-record. No one's gonna know either way."

"And you're being serious?" Sam asks. "You know him? In more than a fed-criminal way?"

"I do," Castiel says. "That's why he was hoping we'd met. He sees me as a friend."

"But you don't see him as one?" Sam asks hesitantly.

"I did," Castiel says. "I visited him in prison for years because of it. That's why I'm staying so far away from this case. I'm not falling back into that trap."

"This isn't something you're saying just to butter me up for something, is it?" Sam asks.

"I'm being completely real with you," Castiel says. "I'd like to think I know how you feel, and you know how I feel."

Sam hesitates before saying, "You're right. I let him go, and I shouldn't have. As much as I hate him, he's my brother, and he was here, and I just..."

"He charmed his way out of it," Castiel finishes for him. "I know. I get it. But I also know that you and I are the best chance we've got to catch him. He's usually very removed and methodical, but he gets sloppy when he's distracted. He's risked a lot to get my attention. He risked a lot coming to see you. If we want him off the streets, we're going to have to use that. That's all I'm going to ask of you. If you see him or you hear from him at all, tell us. Tell me. You've got my number now."

"I will," he says. "I mean, I hope it doesn't come to that, but if it does, I will."

"Thank you," Castiel says.

"No, thank you," Sam says. "I thought I was crazy. I feel a lot better knowing that I wasn't the only one he got to."

"I felt the same way," Castiel admits.

And, the worst part is, everything he said still applies. He hates Dean Winchester. He really does. But if that guy knocked on his door, Castiel isn't sure he'd be able to kill him. He's just that good, and it's scary.

A/N Taylor Swift just surprise dropped a new album and it's gorgeous. It might be her best one yet. It's so soft and gentle but it's also heartbreaking as fuck. She started it in April and finished it last week. It's her first non-autobiographical album, and every song is a story, some from characters she made up (there are three songs that make a full story of three members of a love triangle at different points in the relationship, and if I had to guess, I'd say it's Betty, Illicit Affairs, and Cardigan?), there's a song about the people who used to own her Rhode Island house, and one about her grandfather in the war. It sounds weird and sporatic but it all flows so well from one song to the next, and I can't recommend it enough. The critics are eating it up. 

The whole album is heartbreaking, but this is the only genuinely dark song (and possibly my favorite but jury's still out on that) so it felt fitting here

https://youtu.be/6DP4q_1EgQQ