That something was Grace transported 16 years into the future, where she met her daughter Athena and visited her own grave — learning she had died while giving birth to her child.

ANDREW CHAMBLISS: I think the way we got to the idea was we were really looking for a way to connect Grace to her unborn child and trying to figure out how we could invest her in a way that was very real, and also invest the audience in the relationship that she was going to have with this child.

That led to the idea of having this take place in this unconscious world while she's knocked out.

IAN GOLDBERG: That came from some very and exciting conversations with director Mikey Satrazemis from the get-go of what this world was going to look like, how we were going to differentiate it from the real world, but also kind of incorporate this bleed between Grace's memories, Grace's subconscious, things that happen to Grace in the real world, that are suddenly bleeding into the vision in that Eternal Sunshine way.

It's really magical and beautiful, and it just brings you into this world that you want to be a part of.

I think Mikey just realized it so beautifully.

CHAMBLISS: I don't think we should read too much into it, because this really is kind of Grace's projection of what she thinks the ideal future will be if everyone kind of fulfilled who they were.

I think for Alicia, her story is kind of going down this path of learning to really rely on herself, asking herself who she is and what she wants, and the idea that she would go back to the baseball stadium and turn it into what her mother wanted to make it is really just speaking to Grace kind of imagining Alicia fulfilling herself.

While it was the most gut wrenching ending for the story, it felt like, unfortunately, a very true ending to the story and also gave voice to something that I think a lot of people go through just in life.

We wanted to tell that story, that's difficult and heart-wrenching thing that a lot of people go through and tell it through this prism of Grace and Morgan's relationship, seeing how this dream that they had, that we've been building since the beginning of the season, doesn't come to fruition the way that they'd hoped.

I think you hit it on the head when you talked about Grace firmly believing based on this vision that she's had, that the future is going to be okay because of what Athena is going to bring to it — of how she's going to rally everyone, and unite everyone, and that's how they're going to overcome everything and resolve their differences.

He thought it was about this family that he was going to help protect and nurture, create a future for, and now that's off the table?

That's the big question that he and Grace and by extension, all of our characters are going to have to grapple with now.

CHAMBLISS: I think what she saw in her vision of the future and how everyone turned out was really seeing the best in all of them, based on her experience with them.

This is what Ian was just kind of hinting at, without something to bring out the best in them, it really is going to be a tough journey ahead.

So, all those moments we saw, Strand and Daniel laughing together, or Dwight and Sherry as the happy couple with a couple of kids of their own, Morgan having built this place he wanted to — that is what I think is kind of in danger, and that's kind of what sets the stakes of what everyone could lose in the next four episodes that we have in the season.

I think the other thing just for Grace on a personal level is she is someone who doesn't open up to people.

Morgan helped her do that, but having a baby really was the thing that was allowing her to open up, was to make connections to Morgan, to be able to imagine this future.

So she's going to have some very complicated grief ahead because in many ways, she is alive and the baby's dead and that's kind of the opposite of what she imagined.

Aside from the kind of global ramifications this is going to have for everyone, there's a really kind of interesting and tough personal journey for Grace ahead?

From Morgan's perspective, he knows he handed that key over, so he knows there's kind of a reckoning coming on top of kind of all the emotional trauma that he and grace have just experienced.