'FBI': Zeeko Zaki Previews OA's Most Vulnerable Episode Yet (Exclusive)

The actor talks to ET about Tuesday's big episode and teases Missy Peregrym's onscreen return.

On the latest episode of FBI, OA is about to be at his most vulnerable. Titled "Victim," the normally strong-willed FBI special agent finds himself on the other side of the law, when he's violently attacked and mugged in broad daylight just as he's about to head in to investigate a case amid a series of brutal assaults that has left New York City on edge. The experience, which he keeps secret from his partner and colleagues at the FBI, shakes OA to his core.

"We've been spending so much time building this strong superhero-esque character and person that is OA, it was really fun for me to play the absolute opposite -- shake the confidence in the character," FBI star Zeeko Zaki told ET in previewing Tuesday's hour. "I think showing OA's softer side has always been one of my favorite things to do because as strong as he is, there has to be that other side to it to balance it out. I'm really lucky that we get to play both sides and show both sides, and hopefully it is portrayed and conveyed in a positive and good way in this episode."

As Zaki tells it, exploring a different shade to OA, one viewers often don't see, was particularly satisfying and a unique challenge to navigate during filming of the episode.

"It was that sensation of covering up a lie and really taking this imposter syndrome to the next level," the 32-year-old actor said. "It was fun to piggyback that off of the imposter syndrome, of course, with being an actor and trying to successfully portray somebody who you might consider to be a better version of yourself. And getting to have to pretend that something didn't happen... is a really, really nice challenge to play."

"To have this secret that shakes everything he's been working towards his entire life to be able to be a protector. In that moment, all the hard work, all the whole house of cards he's been building his entire career comes crashing down, and then you try to pretend that it didn't come crashing down around the people that do care about you and can feel your energy," Zaki continued. "It was a really high-stakes, emotional episode that was definitely fun to play."

Bennett Raglin/CBS

Throughout the episode, it's evident that OA's mugging -- which may be connected to the series of attacks the team is investigating -- affects him to a greater degree than he lets on. As the season progresses, it will have a profound impact on OA's approach to his work and life.

"He has not been hitting a perfect game, but his record is very important to him -- if we're going to pass or fail on these cases. I think someone that takes his job as seriously, his devotion is translated into these kinds of wins and losses, and getting to really see one that he doesn't make it out of scot-free. I think we've now opened up that side of things," Zaki said. "It'll be exciting to see what someone in his position might actually get himself into. And maybe we do get to show some of the more rugged or maybe some of the more raw side of these agents' lives. Just because you're on one side or on one team, protecting and fighting crime, doesn't mean that you're ignored by all of these random acts of violence."

Back in July, Zaki's co-star, Missy Peregrym, confirmed that she was returning to work on FBI after taking maternity leave for the birth of her second child. Zaki said it's been nice having Peregrym back on set again after some time away.

"Everyone can look forward to the return of Missy Peregrym, especially if this emotional rollercoaster that we're going on continues down through episode 4. We'll look forward to an emotional return," Zaki teased. "And I'm excited for everyone to see how the writers, how we've all gotten the opportunity to honor this moment in her return. But it's going to be fun and it's really great to have her back on set. I can't wait to get back into some sort of swing of things before the end of the season or season 6 starts up and it gets crazy again."

As for an episode down the line he thinks fans of FBI should circle? 

"I'm interested in seeing how episode 7, which might air as episode 8 potentially, but I get to spend the majority of it in a surveillance van. And getting to film all of those scenes together on the first day of the shoot and then getting to watch it when it comes down to see how the other side ended up playing it is going to be really fun," he hinted. "So I'm excited from a filming perspective to see that episode."

FBI airs Tuesdays at 8 p.m. ET/PT on CBS.