Mary Steenburgen warns 'this is when it gets really hard' on Zoey's Extraordinary Playlist

With only two episodes left in the season on Zoey's Extraordinary Playlist, Zoey (Jane Levy) is preparing in the best way she can to say goodbye to her father Mitch (Peter Gallagher).

All season long, viewers have watched as she along with the rest of her family has struggled with Mitch's declining health due to his Progressive Supranuclear Palsy (PSP) diagnosis, which has left him without the ability to move his muscles or speak. And in this Sunday's episode, "Zoey's Extraordinary Mother," things come to a head when it becomes clear that Maggie (Mary Steenburgen) is in denial about having to say goodbye to her husband.

"Now this is when it gets really hard," Steenburgen warns EW. "And I've been through this, more than once, when you know you're going to lose someone and you know it's imminent and there's no getting that time back, and you have to make all those kinds of decisions that you'd rather not think about in your life. That's what they're dealing with and it's about the broken-heartedness and sometimes even the humor of all of that. And as usual, it is expressed musically."

After Zoey happens to meet a confident and fearless widow named Deb (played by Bernadette Peters) at a cemetery, she realizes how much her mother Maggie isn't fully accepting what's about to happen so she steps in and forces Maggie to meet with Deb.

"Maggie is lonely, she doesn't have friends that have lost their husbands," Steenburgen says. "She doesn't have anyone to talk to about what that's like. Zoey fixes me up with a total stranger who has gone through this. Maggie is a little bit shy about such things so she's really not interested at first in opening up to a stranger and then the floodgates open."

Steenburgen reveals that she and Peters shot many different versions of the powerful scene where Maggie finally opens up about her feelings about losing Mitch, and she's excited to see which one made the final edit. And working with Peters in such a majorly emotional scene was "brilliant."

"I loved doing those scenes," Steenburgen says. "She's such a powerful actor, and she was such a great partner to work with. And she is such a beautiful soul and it was just very moving doing this with her. I’ve been a huge fan of hers for years and I’ve gone backstage of various shows she’s been in to tell her that [laughs] so to finally get to work with her was amazing."

And that's not the only big guest star in the episode. Zoey's Extraordinary Playlist producer Paul Feig also steps in front of the camera as Dale, a charming and somewhat hard-driving salesman that the family meets with at the cemetery while making plans for Mitch's final resting place. "It was thrilling to have him around, especially on camera," Steenburgen says of Feig. "He was working [behind the scenes] for so much of this season that we didn’t get to see that much of him and he’s hilarious. I ruined quite a few takes from laughing because of him. We had the best time together."

And as the Clarke family prepares to say goodbye to Mitch, the cast and crew of Zoey's Extraordinary Playlist also have to prepare to potentially say goodbye to Gallagher as a member of the cast at some point as well, which Steenburgen says is just as emotional.

"There's not a single cast member who has not gone up to [creator] Austin Winsberg and said, 'You have to figure out how to keep Peter around!'" Steenburgen says with a laugh. "I've done it maybe 20 times too. Peter is just one of my dear friends, I love him so much. He's such a remarkable human being and such a crazy talent that every single person on the cast and crew is in love with. The idea of him not being there, nobody had to work at any tears. Honestly, we had to work at stopping the tears. And that's the truth. I still don't even accept it. No, you have to figure out a way for Peter to be there somehow. He's just such a part of all of this and a part of all of our hearts. He's so special."

But as the NBC musical drama gears up for next week's season finale, Steenburgen hopes that no matter what, viewers will be "inspired" with how season 1 ends.

"We gave both these characters and also our audience a piece of all of our hearts in the last episode," she teases. "We couldn’t have known what the world is dealing with right now but it’s coming at a moment in time where it’s a special gift because we’re all needing to laugh and be joyful and we’re all needing to breathe and grieve the loss of people we love and the loss also of our freedom and our connection to people we love, holding people we love. I think people will connect in a very deep way because of this."

Zoey's Extraordinary Playlist airs Sundays at 9 p.m. on NBC.

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