All season long, The Blacklist has been teasing one major mystery: Whose bones are in that duffel bag and why does Red (James Spader) want their identity to remain a secret?

The Season 5 finale ripped off the veil of that secret, and it's a DOOZY. Though theories of whose skeleton was in that bag ranged from Liz's mom to Red's other daughter to the REAL Liz, the real truth was... are you ready for this?

The bones belonged to the REAL Raymond Reddington, and the Red we knew was an impostor this whole time. Yowza!

Liz (Megan Boone) found out the truth thanks to working with the finale's blacklister (played by guest star Julian Sands), so she knows Red's secret but Red doesn't know she knows. That sets up a very juicy sixth season of The Blacklist, which will be answering all the questions we have remaining, like who the heck is this guy then?

But why wait until next season? We chatted with The Blacklist creator Jon Bokenkamp to figure out how long this twist has been in the works and who this mystery person we thought we knew so well actually is.

<p>James Spader, The Blacklist </p>

James Spader, The Blacklist

I know you won't be able to give me answers to a lot of the questions I have, so I will start with this easy one: How do you get someone to talk with hickory briquettes and a squirt gun?
Jon Bokenkamp: Well that is a patented secret by Brimley, he has very unique uses for charcoal briquettes, rubber hoses, candle wax... his garage is a pretty strange place to visit. But he gets the job done. We were trying to figure out what that was, it was hickory briquettes and something, we had something else in there, and I remember Spader saying, "It's a squirt gun, it's gotta be a squirt gun." So I can't take credit on that one.

OK, so how long have you known that Red as we knew him wasn't Red?
Bokenkamp: Since we started the show. It's something we talked about very early on, and it's something we've been working toward. And I hope that fans who are diehard could go back and find little moments and winks and nods. I would give you one example from Season 1, when Liz flat-out asks Reddington, "Are you my father?" and he says, "No." It goes back that far, and it, quite frankly, is a relief to let everyone in on that truth.

Yeah, because early on when we all did press for the show, we suspected that Red was Liz's father. And you were very cagey about being able to give a straight answer. Is there some sort of vindication now?
Bokenkamp: You know what? I feel great that our writers room and the people who are telling these stories have had such a laser focus on a really clean mythology. I know at times it feels like things aren't adding up, it feels at times that we wander, but the truth is I don't think we could get to where we are if we were just winging it. And that's not to say we don't occasionally wing it, but it's like a math problem, the story we're telling. You kind of have to know what you're working toward, you have to have an answer to lay out these stories. So yeah, it's very gratifying to see it come together, and I think the last act of tonight's episode was an example of that, even within that episode. We had a very specific storyline that was laying out, and at the end we saw that it all came together in a way that we hadn't perhaps seen.

Were you always planning to reveal the secret at this point in time of the series' run? I know you can't plan ahead because you don't know how long a series will run, but did you ever want to get this out earlier?
Bokenkamp: Absolutely. [Laughs] That's one of the hardest things, gauging when these reveals come. I was dead-set that it needed to be the end of Season 1, I thought it needed to be the end of Season 2. We had some rather smart partners at the studio and network who wisely suggested that maybe we shouldn't race through the story. We knew we would eventually get here, and it felt like the right time to really lay out a big reveal like this. It's hard to resist racing through our mythology so quickly.

You were really considering doing this at the end of Season 1!?!?!?
Bokenkamp: A lot of crazy things have been pitched. It might not have been a very long-lived show had that been the case. [Laughs.] I think it was right to wait, because it was much better because there was an opportunity to lay in so many clues and to play with that truth. But yeah, at one point I was absolutely convinced, and I think [producer John] Eisendrath talked me off the ledge of why that was a bad idea.

OK, here are the questions I'm sure you can't answer, but I will ask them anyway. Who is this person who has been pretending to be Red? And when did he assume the role of Raymond Reddington?
Bokenkamp: Well I think those are both questions that you have to come back next year to find answers for. Obviously, it is a long con that's been going on, this man has been living as Reddington, has assumed that identity I think many years ago. But who he ultimately is, what his agenda is, why Elizabeth Keene is important to him, why he's working with the task force, I think that's all yet to be understood. The one thing that I think is interesting, I remember talking to James [Spader] very early on, we were either shooting the pilot or had just finished shooting the pilot, one thing that he liked about the pilot is that by the time he got to the end of it, he almost knew less about the character than he knew when he started reading the pilot. And that's a trait that we should embrace in our storytelling, that Reddington is an incredible enigma, and the moment you think you understand who he is, you know nothing about him. It is something that we've come to understand as sort of a core principal of who this character is.

With what we know now about Red, the character Spader plays, does this now mean everything he's said has been lies? Have all these adventures he talks about been big fibs?
Bokenkamp: I don't think they're all lies. That's tricky. Those stories, whether they actually happened, they're sort of like fishing stories. Maybe they happened, maybe some details have changed. But he's certainly a man who loves life, lives every day as though it may be his last, and if they didn't exactly happen as he told them, they certainly happened like that in his mind.

Ryan Eggold, Megan Boone; The BlacklistRyan Eggold, Megan Boone; The Blacklist

Liz at one point says that the bones in the bag belong to her dad. Can we take that as an absolute truth? Or is there a chance that Spader's Red is her dad?
Bokenkamp: No, I think you can take that to the bank. These are the bones of Raymond Reddington, and what we have confirmed on the show is that Raymond Reddington is her father.

Earlier this season we had a bit of a nature versus nurture question, in that Liz seemed to embrace Red's blood that she had in her and we assumed this was a case of nature. But now we know she had a different man's blood in her, and her behavior seems to be a case of nurture as she's picked up on things from Spader's Red and Tom.
Bokenkamp: Well I think that's the big question, right? I don't know, even as a parent, which is right. At times, depending on the contact, nature versus nurture, it's hard to tell. But I think there are certainly some things that have come about in her life that are only because of the people she's been surrounded by. They have very clearly defined who she is as a person, and they are going to motivate her as we push into Season 6.

Liz knows that this Red isn't her dad, but he doesn't know she knows. I love how Liz has changed this season, and it seems like we're heading into Season 6 with her having the upper hand for once. How will that dynamic change, will Liz be in power next season?
Bokenkamp: I certainly think so. What is unique is for the first time in the life of the series, we know and Liz knows something that Red doesn't know. She has a truth about him that I don't know she has any intention of telling him about. If I were her, I wouldn't say a word. I'd take a cue from my now-deceased husband and play as a double agent. I think she is really in the catbird's seat, and is positioned to explore this man's true identity in a compelling and dangerous way. We have some really exciting stories to tell out of this new dynamic.

The Blacklist will return for Season 6 in 2019.