The "Alive in Tucson" gang are faced with another shocking reveal and THR caught up with an actress behind it all.

[Warning: This story contains spoilers from Sunday's back-to-back episodes of The Last Man on Earth, “The Do-Over” and “Pranks for Nothin'.”]

And then there were two — two more, that is.

The life of former last man on earth Phil Miller (Will Forte) got just a little bit more crowded, as Sunday’s episodes saw two more survivors — Gail (Mary Steenburgen) and Erica (Cleopatra Coleman) — join the ever growing “Alive in Tucson” gang and complicate things even further.

As Phil’s frustrations with wife, Carol (Kristen Schaal), reached an all-time high, Gail and Erica's arrivals were seen as a godsend. Seeing an opportunity, Phil lied to the new pair about the other survivors in the hopes of sleeping with getting a “do-over” with them.

Needless to say, when the rest of the survivors found out, everything went to pot, as Phil realized that he’s a horrible liar and Carol finally divorced him.

With the world of the show continuing to expand and grow, The Hollywood Reporter caught up with new group member and 2015 guest-star extraordinaire Steenburgen (Justified) to discuss the Gail character, keeping secrets, and what’s next for the group.

After the blowup with Phil, Carol had quite a few harsh words for your characters. Do you think that was fair, given that he was the one who lied? Will she ever forgive them and move forward, or will that always be a source of tension?

Kristen’s character had Phil all to herself at one point, and then had share him with Melissa in some ways, and then we come along, which is probably more than she can take. It was probably just her frustration and the reaction to more invaders on her world and her marriage. So, she changes a little bit in her attitude towards us but I don’t think it’s ever, by the end of this year, fully settled. The jury’s still a little bit out as far as she’s concerned.

Now that Gail and Erica have joined the other survivors how will they fit in with the group going forward?

I don’t have all the answers to that because I [only] did five [episodes], so we were still a fairly new part of that world, even at the end of it. [For season two], there’s going to be lots of discussion about where these characters evolve and where they go. I know a few ideas they have for my character and they were very interesting and very out-of-the-box thinking, and are quite different than what I started out as.

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There was a lot of innuendo surrounding your character’s relationship with Erica. How much will we learn about that relationship and see it develop as the show goes on?

There’s definitely other references to it. They didn’t know anyone existed but each other, so that was part of that, but they genuinely like each other and, as buddies who have been through all types of stuff together (laughs), they each will have their own unique reactions to this new world that they enter.

You’ve guest-starred on quite a few shows with strong comedic voices behind them, including Togetherness and Curb Your Enthusiasm. What was the biggest difference in working with the Last Man on Earth team?

With Will, there’s the added component of the fact that he’s doing the scenes with you, which was true with Larry [David] too, so it’s not just the comedic voice but it’s also the actor that you’re working standing in front you. There are some things that are very alive about that. Will is not at all precious about any preconceived ideas he had or any script he had been heavily involved in writing, so he’ll play with that and jump off from that and improvise off that. Of course, Curb was fully improvised, there wasn’t any script. [For] Last Man on Earth, I loved the read-through days because the scripts were so much fun and Will just keeps mining them for humor and finding little moments and encouraging us to do the same.

You were also on FX’s Justified this year. What’s the biggest difference in working on a show that’s just ending compared to a show like Last Man, which is just getting started?

Justified was such a specific thing because it not only had been going all this time and the actors have been living in these characters for five years before I came on, but it was also in the voice [of] Elmore Leonard originally, who was even part of the show before he passed away. It was like going to stay in a house that was completely decorated and absolutely fantastic and where you have a good time and go play, as opposed to walking into a fairly empty house that you pull together yourself. I’ve clearly been watching too much HGTV (laughs). Whenever we start a new TV series, there’s also a lot of question marks, and part of that is finding who you are. There is a wonderful improvisational light to it that I really enjoyed as well.

The show has been picked up for season two. What was your reaction to knowing that you’d be back for another year?

By the time we did the last episode, there was an incredible camaraderie among us. [We had a] really insane email chain that went on for many hours when they announced [season two]. It just got more and more demented. We’re all excited to be a part of something so exciting and unique. Even the show is very different from any other show I’ve been on, with the lack of electricity, and our world in Tucson, and this set, the collaborations with everyone, whether it’s the art department or production designers, everybody went wild with their own imaginations. I [have] the best time being part of all that.

What did you think of this week’s episode? Excited to see more of Gail and Erica? Sound off in the comments below. The Last Man on Earth airs Sundays at 9 p.m. on Fox.