Warning: Spoilers ahead for "The OA."

Ian Alexander stars on Netflix's "The OA" as Buck Vu, and the role was expanded for season two to include "Michelle," a different version of Buck we see in a new dimension.

In an interview with INSIDER, Alexander reveals how he drew an antler design that said "Buck Vu" for his character's costume and helps explain the details of the final mind-bending twist.

Netflix's "The OA" took its characters to literal new dimensions with "Part Two" of the mind-melting show. One of these people, Buck Vu, is played by 17-year-old Ian Alexander.

This season, Alexander was tasked with portraying Buck Vu (a transgender teen boy) as well as Michelle Vu (a version of Buck in an alternate dimension who Alexander views as a pre-transition character). Similar to Buck, Alexander identifies as transmasculine and uses he/him pronouns.

Alexander had a creative hand in crafting his role on the show, including drawing his own custom artwork for a T-shirt Buck wears for most of his "Part Two" scenes. The drawing of antlers spells out "Buck Vu" — a detail even the show's co-creator Zal Batmanglij didn't pick up on.

"I created it, so I can't see anything else when I look at it," Alexander said in an interview with INSIDER. "But even the director and even people who are watching it like two or three times didn't even notice until I pointed it out."

Alexander spoke with us about how he watched (and rewatched) the new episodes right at midnight when Netflix released them and helps explain exactly what is happening on the last few minutes of the "Part Two" finale.

Ian Alexander as Buck on the first season of "The OA." JoJo Whilden/Netflix

Renfro: What was your initial reaction to the "Part Two" scripts, particularly with Buck's journey this season?

Alexander: I knew a little bit ahead of time because Zal [Batmanglij], the director, called me ahead of time to ask me if I was comfortable with potentially playing two different roles in part two. But I didn't know exactly what the involvement was going to be of the two characters, so it was definitely super exciting reading through it the first time and seeing how they tied together the two different dimensions and how I was involved in both as Buck and Michelle.

At first, I was a little concerned just because in part one, Buck and the boys and BBA are involved in every episode. So I was like, "Oh no! Where's Buck? Where's our story?" But then when I got to episode three I was like, "Oh, OK, I see. It's all worth it, it all leads up to this moment."

I was actually really excited to have two episodes dedicated to just us and our story. It really gives us time to breathe and to grow and for audience members to really empathize with our characters, rather than just getting little glimpses of us. So, yeah, I was definitely a little cautious about that at first but then excited once I saw how it all played out.

Renfro: Have you watched all of the episodes now that it's out on Netflix?

Alexander: Yeah, I've actually seen all of it twice now, and I'll probably watch it for a third time this weekend if I have the time. I couldn't wait, I stayed up until midnight [on Thursday] so I watched it just as it was released.

Renfro: While re-watching it, did you spot things that you hadn't noticed before about the story while you were filming?

Alexander: Absolutely, yeah. Especially even though I was filming at the show in the second dimension, my character is missing and/or comatose so I didn't really have any involvement in that storyline. So it was really exciting to see how it played out with OA and Karim and the others because I hadn't seen any of that. I'd only just read it in the script.

And on the second watch through I was able to kind of put aside my own criticisms of my performance and everything. Because that's why I watched it the first time just by myself, so I could get that out of the way. Then the second time I was able to enjoy it and focus on the background and the details and stuff like that.

I think I definitely want to watch it a couple more times because there are so many little Easter eggs and little hints and clues that you don't really catch on the first couple times around.

Renfro: When the photos for "Part Two" first came out, you tweeted about the shirt Buck is wearing in one of them and how there's a detail in it people were missing. Can you explain that a little bit more for anyone who missed it?

Alexander: I went in for a wardrobe fitting last year [...] and Zal told me, "I really want you to design a shirt that Buck is gonna wear throughout 'Part Two,' and it'll become an iconic look for the character."

I sat down that night and sketched a bunch of stuff. I wanted it to be related to Buck's name, so I was playing around with some ideas of a male deer. I mentioned the idea of wanting to put deer antlers on a shirt, and [one of the wardrobe designers] said, "What if you spell something out with the letters?" And so then I was like, "Oh, I could spell out Buck's name in the antlers."

I sent the initial sketch to Zal and he loved it. I thought he saw that I spelled out Buck Vu, but actually, he didn't notice it until they created the shirt and I wore it to set my first day shooting as Buck. I made some sort of comment saying, "Oh yeah, I'm so glad you like my Buck Vu design." He just looked at me and was a little confused.

You can see the "Buck Vu" design on the T-shirt here. Netflix

I said, "What? It spells out Buck Vu," and he was like, "Oh my god! No way!"

He was calling people over to look at the shirt. Some of them were like, "Yeah, it's obvious" but other people were like, "Oh my god, I had no idea!"

It was funny to me since I created it, so I can't see anything else when I look at it. But even the director and even people who are watching it like two or three times didn't even notice until I pointed it out. It's a really cool little Easter egg for repeat watchers.

Renfro: Rewatching both parts, I noticed a lot of links between Buck and Rachel. In part one, there's the episode that opens with Buck singing in front of his mirror and then riding his bike past a red backpack and what looks like the aftermath of a car accident, which is reminiscent of what Rachel described in another scene. They also both sing, and then Rachel comes to Buck through his mirror.

Alexander: Yeah, absolutely. I was talking about that in another interview where they asked me why Rachel goes to Buck. And part of it is because he leaves the door open. He still believes in OA, whereas the others doubted her or they've lost hope. But Buck still has this strong hope and belief that she's still out there and they still have to help her.

Ian Alexander and Brendan Meyer as Buck and Jesse on "The OA." Nicola Goode/Netflix

But also, I was thinking it's because of their voices and their connection. In dimension two, Rachel is mute and it's hard for her to communicate, but she travels into Buck's mirror since they both sing — that's something they have in common and that's how she's able to communicate.

So yeah, I definitely have been noticing the parallels between them since part one, but they fully dive into that in part two and acknowledge the fact that there is a connection between Buck and Rachael.

Renfro: My interpretation of it has been that OA is surrounded by a different "tribe" — that's the word I use, for lack of a better term — but it's like each person in that tribe kind of has a link to another second dimension.

Alexander: Yeah, absolutely.

Renfro: I would also love to talk to you about the final scene since that is such a trippy, complex, and surprising way for this season to end.

"The OA" went very meta for its second season finale. Netflix

Alexander: It's very meta.

Renfro: Yeah, it's meta but then once I sat down and looked at it, it's not like a full breaking of the fourth wall because there are still these changes from our reality. Can you walk me through your understanding of what is happening in that scene?

Alexander: So essentially, Michelle successfully jumped through the Rose window into the third dimension. Which is very similar to our reality outside of the show. But it is different because obviously Brit Marling and Jason Isaacs aren't married in real life. But it is a dimension in which they are creating the show called "The OA."

They even referenced it [when an earlier character told OA]: "Everyone will call you OA but you yourself will not." They eluded to the fact that they're creating this show called "The OA" and then when Karim has the view into it, he sees the set and how it parallels exactly what he was experiencing.

So Michelle jumped into the body of "Ian Alexander," and is trapped there, and doesn't know how to return back to dimension two. But when Karim calls out to Michelle, she's able to realize, "Oh, I need to go back to the rose window."

It's not really confirmed whether or not — once Michelle has jumped through back into dimension two and wakes up from that coma — if "Ian Alexander's" consciousness is no longer repressed and it comes back. You're not really sure what happens to "Ian Alexander" but that's stuff that we'll certainly have to see in part three if it gets picked up.

Ian Alexander as "Ian Alexander"/Michelle on "The OA" season two finale. Netflix

I definitely feel like it's gonna be very interesting to see how Steve jumps into "Paddy Gibson's" body and then chases after OA in the end. Yet again, this parallels what happened at the end of part one. But instead, this time, instead of the ambulance escaping him and OA's body and consciousness escaping him, he is able to confront it and confront Hap as well. So yeah, it's definitely something that I can't fully 100% explain because I don't have all the answers.

So Hap jumped into "Jason Isaac's" body, OA jumps into "Brit Marling's" body, Karim still remains Karim because he didn't quite fully jump, he was just able to see it. And then Michelle jumps from "Ian Alexander's" body back into Michelle's body.

Renfro: Right.

Alexander: [Laughing ] Yeah. It's very complicated and confusing, but that's the best I can do.

Patrick "Paddy" Gibson plays Steve on "The OA." Netflix

Renfro: Did you ever get headaches on set while you were trying to figure out like, "I'm Ian but 'Ian' for this scene?"

Alexander: The first day we shot that scene on the soundstage, there was actually a bit of confusion on what I was supposed to wear for wardrobe. Initially, they dressed me up as Michelle because they thought I was just supposed to be playing Michelle that day.

But before they put the wig on I was like, "No, actually I'm supposed to be Ian Alexander today so I just need to have my natural hair." We had to exit the hair and makeup trailer, go onto stage, and consult with Zal [Batmanglij] like, "What am I supposed to be wearing in this scene?"

So yeah, it definitely caused a lot of confusion 'cause I would hear crew members being like, "Wait, what dimension are we in? Are we in three? Are we in two? What's going on here?" But I think everyone managed it well and it turned out really great.

This interview has been edited and condensed for clarity.

"The OA" is streaming now on Netflix. You can read all of INSIDER's coverage of the series here.