[WARNING: The following story contains spoilers bout Sunday'sepisode of Quantico. Read at your own risk.]

Quantico filled in some major puzzle pieces on Sunday, not the least of which came in the final minute, when The Voice instructed Alex (Priyanka Chopra) to give her phone to the driver of a car. Who was behind the wheel? Shelby (Johanna Braddy).

Shelby will (presumably) drive away with two people in the backseat: Simon (Tate Ellington), whom The Voice had ordered to hop in, and Will (Jay Armstrong Johnson), whom Alex and Simon had extracted from the CIA as part of their final task for The Voice. Will had been held as an asset for the past seven months because he had cracked the NSA encryption software and memorized all the U.S. military codes (cannot make this up!), so the terrorist probably wants him for that.

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Meanwhile, in the past, while the rest of the class tried to figure out how to illegally cross the U.S.-Canada border (again, cannot make this up!), Caleb (Graham Rogers) convinces Shelby to meet her parents, Laura (Kelly Rutherford) and Glenn (Kevin Kilner), who explain why they faked their deaths in 9/11. Their company, McGregor Wyatt, through an intermediary, had sold the Taliban the software used in the attacks. Spooked that they will lose everything, they changed their flight manifest to fake their deaths and used Samar to con keep in touch with Shelby. Shelby buys it all, but Caleb soon learns that they are still trying to con their daughter. He offers them $5 million on the spot if they leave her alone forever.

So why is Shelby driving that car? And why is she so damn gullible? See what Braddy says below.

What is Shelby doing in the car?
Johanna Braddy:
That I know I cannot tell you! It looks really creepy and really incriminating. I think at this point Shelby is involved in something not so great, but I can't reveal any more than that. ... Shelby is alive past that moment, so you will see her and she will have interactions with humans. [Laughs] You're not going to get a lot of answers right away about what she's doing, but it's so good.

How were you playing it, not knowing what her motive is at the time?
Braddy:
For me, through the whole series, because we hadn't been told who the terrorist is, in my head, I've always had to justify why it would be Shelby, so that if it is her, looking back, the performance would be true. So in my head, while I was doing that [scene], I am not the good guy in that situation. And going from the past, Shelby and Alex's relationship has significantly changed, so that was what I was trying to portray — she being the bad guy.

Do you know right now who the terrorist is?
Braddy:
We haven't shot anything yet, but I know. ... I think everyone was surprised [by who it is]. We all had different theories. It's going to be a good reveal. A lot of people didn't want to be the terrorist, but I've always said from the beginning I would be up for it. I think it's a really cool job and I've told Josh [Safran] that from the beginning. Whatever's best for the story line, sign me up!

If she's not the terrorist and has just been captured by the terrorist, do you think the terrorist is preying on Shelby's hatred of Alex?
Braddy:
Potentially. That would make a lot of sense — using someone who already hates her. That would also put Shelby in an interesting spot because part of her maybe does want to see Alex taken down and suffer.

Are Alex and Shelby going to repair their relationship? Can she rope her onto Team Alex again?
Braddy:
That I really don't know. Alex and Shelby's relationship is a big part of Quantico, so fingers crossed they become friends again. But Shelby is really hurt by what's happened since the bombing. I think it's a matter of if she can forgive Alex.

We haven't seen Clayton (Mark Pellegrino) in a while. Will we see him and Shelby start their affair?
Braddy:
You'll see a little bit more of him in the past.

Let's talk about Shelby's parents. Will Caleb tell her that they're still conning her?
Braddy:
I don't know. At this point, Shelby is 100 percent sold that she and her parents are one big happy family now. She's planning her future. Her life's kind of going up at this point and I think anything that shakes that up would severely shake up her psyche for her future story line big time, to be screwed over twice.

Why is she so gullible? She was conned for 15 years and after 10 minutes with them, she's falling for it again.
Braddy:
That's a great question! [Laughs] You know, there are quite a few things that happen where we're like, "Wait a minute, we're supposed to be the best FBI agents ever." But I just think maybe it's her optimism. She's lived for 15 years without her parents and she latched onto the one person she thought was her sister. She didn't have any family left. I think in desperate times, your mind isn't as sharp as it should be. I think with work, she's fine, but you can have someone who's super-strong with their business, but their personal life is all out of whack. I think Shelby is a perfect example of that. ... I think she's totally going off of emotion. She's not thinking straight. She should be asking some more questions, especially as an FBI agent!

That was a pretty shady story they told her. Is that story true?
Braddy: That I don't know. I never thought about it. It could be another lie. It was very shady.

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Do you think Shelby has fully forgiven them? She was totally against meeting them and by the end of the episode, she was planning their next meet-up.
Braddy:
I think honestly meeting them, all that anger and aggression melted away. She cares about them. It was easier not to see them, but being reunited with your parents you never thought you'd see again, it kind of turned her to mush. I think she's sold. She's all-in.

Is there a part of her that thinks they're still playing her?
Braddy:
No. Not at this point. I think love is clouding her judgment. It's really sad. She's got some bum deals this season. ... She's trying to continue that relationship. There's no way she wants it to end after one meeting. She's blissfully ignorant right now.

Do you think Caleb is holding back from telling her because he feels guilty since he's the one who pushed her to meet them?
Braddy:
Probably. She didn't want to and he made her. To find that out, I think he feels super-guilty and doesn't want her to be hurt again. She's gone through so much crap in her life. She's become a strong woman, but she's starting to break. That would be the final straw potentially. That will also put a nail in the coffin on their relationship. They've been so on-and-off for months, so that won't be a very good situation for her to find out from him at least.

Now that she's ostensibly reunited with her parents, are we going to see a new Shelby in the past? Is she happier now?
Braddy:
Yeah, you'll see a little shift with her. I want to see what people notice. We've changed slight things with makeup and wardrobe, little things, because a chapter in her life in her mind has been closed. This horrible event never really happened, so in my head, she's different.

When will Shelby learn about Mark Raymond and Sistemics?
Braddy:
That is coming up next week. We all want to know what's going on with that.

It's not fair that new guy Will knows everything and Shelby doesn't.
Braddy: I know! She never knows anything! ... I think that whole story line is freaky. Cults freak me out. Caleb's swishy. You trust him one minute and then he totally betrays you. I don't know I feel about Caleb Haas. I don't know if I trust him to be so innocent in that situation.

What's Shelby's reaction when she finds out about Mark Raymond?
Braddy:
Well, I would be a little confused if I found out my boyfriend was two people. But Shelby's an FBI agent, so she'll do more digging. ... She tries to get involved with Iris (Li Jun Li) and figure that whole situation out. There may or may not be a confrontation with Caleb. But she and Iris have actually started to bond. She's not quite the nemesis we thought she would be.

She was looking out for Shelby too with the whole envelope situation.
Braddy:
Yes, she did. I think in the early days, maybe it seemed like Iris was trying to go for Caleb or something, but they've veered away from that and they've actually formed a friendship.

Are we going to see Iris or Drew (Lenny Platt) in the future? We only just got Will in the future this week.
Braddy:
Oh, that's right. I don't know. That's a great question. We're still finding out what's happening. We learn new things every episode.

What else can you tease about the terrorist reveal?
Braddy:
I think it's going to surprise a whole lot of people. It's a good one. We still haven't been told motive or anything. We're on [Episode] 21 now. We just know who she or he is, so we're all excited. We're all anxiously awaiting the next script.

Quantico airs Sundays at 10/9c on ABC.