On a show called Agents of S.H.I.E.L.D., one would assume that the series would tackle something as big in the Marvel universe as Life Model Decoys right away. But the introduction of LMDs didn’t come until a third of the way through season four, after it was revealed that A.I. Aida (Mallory Jansen) secretly swapped out Agent May (Ming-Na Wen) for an LMD without any of her teammates realizing.

After the ABC Marvel series spent the first stretch of season four focusing on Ghost Rider (Gabriel Luna), the next group of episodes are going to focus on the LMD mythology in a big way. May’s swap opens the door for other agents to get replaced by LMDs without anyone knowing, including viewers. But why did S.H.I.E.L.D. wait until now to explore LMDs?

“The short answer is that [executive producer] Jed Whedon walked up one day screaming, ‘Aliens vs. robots!'” executive producer Jeff Bell joked to Nerdist along with a group of reporters on a recent set visit.

“That’s true, we wanted that to be the tagline of the season,” Whedon said with a laugh. “It’s something we wanted to do for a long time. When you start a show called Agents of S.H.I.E.L.D., you’re pretty sure you’re going to do it at some point. But we always have to steer away from stuff that’s coming up in the movies, and there were going to be some robots in some of those big movies.” Naturally, Whedon is referring here to the titular villain in 2015’s Avengers: Age of Ultron.

“So we steered away from it initially, but we always had it in our minds that we would do it at the right time,” he continues. “We felt like we had a lot of good Inhuman stuff to do last year so it didn’t seem like the right time. And when we started talking about Ghost Rider, we realized that with the Darkhold there was a way to get all of these things in one soup. That’s how it happened this year.”

According to Marvel TV boss Jeph Loeb, there was also another reason why they waited until now to introduce LMDs to S.H.I.E.L.D.: “As you do with any show, if you’re going to do a storyline where your main characters might be replaced at any point, you want to make sure that the audience is fully invested in these characters,” Loeb said. With Ghost Rider essentially getting killed/disappearing in the fall finale and May being switched out for an LMD, that signals a major shift of the series moving forward.

“This year there are three [parts to the season],” Whedon said. “It’s based on our schedule and how we’re airing. We like it to run continuous, but that’s impossible. So this next chunk will be a section and then we’re off for a while, so then there’s a third pod.”

Executive producer Maurissa Tancharoen agreed, adding, “It goes Ghost Rider, LMDs … and then puppies and rainbows.”

While the S.H.I.E.L.D. team couldn’t reveal what the third “pod” of season four will be about, they did reveal that it will have something to do with the first two.

“It’s all connected,” Loeb said.

Bell elaborated, “Transitioning from one to the other, it was the Darkhold [that] came out of this supernatural thing, which allows Radcliffe [John Hannah] and Aida to have the information to do the LMDs. So while it becomes more science-specific, everything that we’re doing in the second pod grows out of what we set up in the first pod.”

“The connective tissue will remain apparent through all three parts,” Tancharoen said.

And then Whedon added, “And then we’ll really stick the landing.”

When S.H.I.E.L.D. returns with “Broken Promises,” the mystery of May getting swapped out with an LMD will be dealt with. Bell said, “You will learn the when, the where, the why and the how. We will show you. I just can’t say when we’ll show you.”

Aida creating an LMD will allow SHIELD to finally get into the mechanics of what this technology means for the future of the universe and these characters. “That is a lot of stuff that we’re going to explore,” Whedon said. “It’s sort of a reflection of inhumanity. We’ve seen Aida, that she was supposed to mimic what it’s like being a human, and so we’re starting to ask that question of what [it means] to be a human, what defines a human. Also, we started with some of our characters questioning what kind of people they are, so now we’ll start asking, ‘Are we even people?’ Those questions are what we’re going to get into.”

When the showrunners were asked to tease where the winter premiere picks up, they revealed that viewers won’t have to wait long for answers. “There’s been some reveals and they will be dealt with immediately,” Whedon said. “You’re not going to have to wait around for the ramifications to knock us on the head.”

“We left you with a big WTF,” Tancharoen said. “We all know that Coulson [Clark Gregg] is sitting across from the not-real May.”

Whedon jumped back in with, “And we know that Aida is not awesome. We will deal with that right away, that’s one thing I can tease.”

“You really can’t trust Aida,” Wen agreed.

Whedon added, “With everything. Humans, Inhumans, A.I. It’s not black and white. We’re living in the grays.”

What do you think of May getting swapped for an LMD? Tweet me your thoughts and opinions at @SydneyBucksbaum!

Images: ABC