It’s hard to know whom to believe on “Quantico,” so fans question everything they hear. In episode 5, Simon (Tate Ellington) told Elias (Rick Cosnett) he’d been in the Israeli Defense Forces and went through some traumatic experiences in Gaza. Living his life undercover is his only way to cope. He doesn’t need glasses, and he isn’t gay. He just developed a persona to help him cope with what he’d done, or so he claims. Executive producer Joshua Safran assured viewers Simon didn’t completely lie.

“What Simon says to Elias, it’s not the whole truth, but it is the first time he has been real,” Safran told TV Line. “So while there are definitely pockets within there that he has obscured -- which we will get to learn as we move forward -- that’s not a false confession.”

Safran also explained a rule for the show: When a character claims he or she is going to reveal the truth, fans should expect at least a partial version of the real story. “When people say they’re telling the truth on this show, they actually are,” Safran assured Entertainment Weekly. “Like, when someone sits down and says, ‘I’m gonna tell you the truth now,’ it may not be the whole truth, they may be selective about it, but it is the truth.”

However, much like the audience, other characters are skeptical about what fellow agents claim is real. “When Simon tells Elias, that is the truth. Now, does Elias choose to believe that truth or not? That’s interesting,” Safran added. “I don’t want to say in this case one way or the other, but I think in some people’s cases, they may not believe it, because sometimes the truth is harder to believe.”

Don’t expect the full truth any time soon, though. “Quantico” likes to keep throwing plot twists into its mysteries, and Ellington revealed another one is coming in Sunday’s episode related to Simon that will confuse viewers even more. “There are things that happen in [Episode] 6 that just twists it a little bit more,” the actor told TV Guide. “There is stuff that comes up in 6 that still makes it like, ‘Well, did he give an answer or not?’ That's what I want. You're still not sure even when he seemingly gives you an answer, but you're like, ‘Wait, he never really says anything.’ ”

Fans will have to tune in to see if they can figure out what’s real and what’s a lie.

“Quantico” Season 1, episode 6 airs Sunday at 10 p.m. EST on ABC.