Warning: This story contains major spoilers from the season finale of Agents of S.H.I.E.L.D. Read at your own risk.

It wouldn't be an Agents of S.H.I.E.L.D. season finale without a shocking twist.

Just when things were settling down after the Inhumans vs. S.H.I.E.L.D. battle, Fitz (Iain de Caestecker) and Simmons (Elizabeth Henstridge) finally addressed their feelings for one another and decided to go on a date to test the waters. Naturally, things go awry after Fitz accidentally unlocks the crate housing the Kree stone—the same stone that the Inhumans said was lethal to their kind in the wrong hands. Turning into liquid form, the stone absorbs Simmons before reforming as if nothing ever happened.

Fear not, Henstridge is signed on to return for season 3, so Simmons has not met a grim fate. "Usually if it's something really bad, you get a call," the actress tells EW on the set of the ABC super series.

But, really, what the heck just happened to Simmons? "Part of me was thinking, if this is some sort of Inhuman thing then maybe this is like the mist, and it's some sort of gel, and maybe I'll have superpowers, but I don't think I will," Henstridge says. "I think I'm somewhere. I think it transports me somewhere. We've had so many theories on set. 'Maybe she can go back in time and kill Ward,' or 'Maybe she goes back in time and for whatever reason Fitz doesn't know who she is and no one knows who she is,' or 'Maybe she goes invisible and no one can see her,' or 'What if she's just trapped inside the rock?' That would be terrible. There have been so many theories, but I think it's a transportation device."

Henstridge, however, at least appreciated that Fitz and Simmons got to have a long overdue discussion about their feelings for each other before her disappearing act. "Having had that conversation, in her mind, whatever happens to her, she's thinking, 'Well, I know Fitz is going to come and get me because he's my boyfriend now,'" she says with a laugh.

On the plus side, this happened to a "more accomplished" and field-ready Simmons, versus the green agent we met in the pilot. "Her main asset is still her mind," Henstridge says. "She's had basic combat training, but she's by no means a fighter. I do think she's much better at manipulating, lying a little bit or being cleaver in that way, so I do feel much more confident that wherever she is, she's better equipped—maybe not as well equipped as she can be."

Ultimately, Henstridge says she wasn't worried about Simmons' fate, just feeling fortunate to have been along for the ride. "Honestly, I'm pinching myself that I'm still in it," she says. "We've done 44 episodes now and I've been in every single one. It's such a joy to be here. As an actor, you get it—you get that at any point, for the good of the show, you might be killed off or out for a few episodes. At this point, the show is bigger than me or anyone in it. I was more excited about it. I definitely thought, 'Well, I'll wait for a call or not.' It's a strange feeling at this point. We've done two seasons. I never want it to end, but if it ended, I feel like I've really gotten to know this character. If this was the start of the first season, I'd probably be hyperventilating, but I have a strange zen about the whole thing. It's probably because I read it." Henstridge then pauses before reassuring herself as much as the fans, adding, "They would've called me."

Marvel's Agents of S.H.I.E.L.D. will return to ABC this fall. In the meantime, read our postmortem with executive producer Jeffrey Bell here. Also, Brett Dalton talks Ward's Hydra turn here and we go behind-the-scenes to see how they chopped off Coulson's arm here.