Are Nimah and Raina behind the Grand Central attack on Quantico?

If you ask Alex (Priyanka Chopra), the answer is hell yes. After finding footage of one of the twins (Yasmine Al Massri) in Grand Central last week, Alex is convinced that one or both of them are the bombers on Sunday's episode. (Hmm, she sure is quick to blame them after chastising the media for pinning it on her, aka "the brown girl.") As you can see in the exclusive sneak peek above, Simon (Tate Ellington) tries to talk some sense into her.

"Three-quarters of a million people pass through Grand Central every day," he says. "Coincidence is not evidence."

"This is solid evidence," Alex claims. "This is a real lead. ... And with everything that's happened between — I'd understand if you didn't wanna help. But I can't find the twins without you. Please."

Will Simon help her? Watch the clip to find out. Quantico airs Sundays at 10/9c on ABC.