We are only a few hours away from the latest episode of Agents of S.H.I.E.L.D., which means we will finally find out what the heck happened to Simmons. She was lost on the planet for six months, and since she returned, there has definitely been something off about Simmons.

That has escalated to include a mental breakdown in a restaurant and now wanting to go back to the mystery planet. Elizabeth Henstridge spoke with IGN about tonight’s episode and how it will differ from what we’ve seen.

Well, it’s definitely a departure from the usual thing that we do week to week and it’s a very brave choice by the producers and everyone at ABC and the writers and the directors. `And it’s a new challenge and one that I’m not aware has ever been done before on TV or certainly with our show or anything I’ve seen on ABC. So we really get to know what happened to Simmons during those last six months and we get to find out why she wants to go back and also why she was so traumatized when she did get back. It was just a huge feat for everyone involved and I think we’ve pulled off.

They also talked about the secrecy that surrounds Marvel and when she found out what happened to Simmons.

The full story, I probably knew two weeks before we got the script of what had happened on the planet, but in the finale, I didn’t know anything. Where she was going or what was happening. I knew that she wasn’t dead and that was about it. And then when we were coming back… It’s really on a need to know basis. And they hadn’t locked the story in yet exactly. They like to allow the writers creative freedom and so even in the scene where Fitz and I went on a date, it becomes apparent why the wine on that date causes Simmons to go over the edge and get so emotional. I didn’t know why it quite did, I just knew it did. It wasn’t until I read episode five that I understood, “Oh, that was because of that…” I knew it enough time to prepare for the episode, in terms of acting in the episode, but yeah, they keep the secrets close to the chest on this show.

Marvel’s not only secretive about the scripts, but also the episode apparently, being that Henstridge has yet to see what they’ve been teasing as a great performance by her.

I was just so exited and grateful to have something so different to explore. And just the filming of that… we were doing that during a heat wave in a huge desert quarry situation and there were massive, ten foot high fans. It was just very extreme conditions to shoot in, regardless, and it was so nice as an actor to be there. Because Simmons is in an extreme position and what we we had to do is nothing compared to what she had to do, but it’s nice to have that atmosphere to act against, rather than a green screen. We were struggling to stand up, so we didn’t have to act that. I was just very excited to see the blue crush effect. As we were doing it, everybody took a big leap of faith and we have the best people working on our show, so I knew it would work out. But usually you film something and you have some idea of what the end product is going to be like and with this, I mean… I haven’t seen the new episode yet, so I just have no idea what it’s going to be like!

One thing that remains to be seen is why she wants to go back precisely. According to TV Guide, it might have something to do with who she met during that six month period.

We’ll quickly discover that she wasn’t alone.

Though Simmons first thinks the planet’s habitual sandstorms are nothing more than a normal environmental occurrence, she soon learns that they’re a calling card of the planet’s reigning evil, a cloaked figure who kills or drives mad everyone it encounters. Simmons hypothesizes that this creature has been receiving human sacrifices through the portal, much like those in which the Gloucester men in 1839 seemed to be partaking.

What kind of evil presence and possible friend she meets, remains to be seen. Thankfully we should get answers to all of this tonight when “4,722 Hours” premieres. Check out some clips from tonight’s episode here and here, plus a few images here.

Agents of S.H.I.E.L.D. will air episode 3×05 “4,722 Hours” tonight at 9 p.m. EST on ABC.

Sources: IGN & TV Guide