(CNN) -- Even before they had a chance to view it, everyone involved with Showtime's megahit, "Homeland," "knew that it was something extraordinary and special," said actor Mandy Patinkin. The veteran star spoke to CNN at the premiere party for season two, ahead of the show's premiere on Sunday.
In "Homeland," CIA intelligence officer Carrie Mathison (Claire Danes) believes that Marine Sgt. Nicholas Brody (Damian Lewis), a POW returning from Iraq, became a traitor while in captivity and is planning to fulfill a terror plot on U.S. soil. At the end of season one, Brody decides to run for Congress.
Meanwhile Carrie, who suffers from bipolar disorder, realizes why Brody would turn on his country just as she's about to undergo electroconvulsive therapy that will erase her short-term memory. Season one received nine Emmy nominations, and picked up four of them at the 64th Primetime Emmy Awards, including outstanding drama series.
If you've been wanting to get into "Homeland" or catch up before the new season premiere, there's still time. Season one was recently released on DVD/Blu-ray. In addition, Showtime will air a marathon of all 12 episodes of the first season on Saturday, September 29, beginning at noon ET/PT. Season two premieres Sunday, September 30, at 10 p.m. ET/PT.
To kick things off for Sunday's return, Showtime and Time Warner Cable hosted a screening and reception at the Intrepid Sea, Air and Space Museum in New York. Among the attendees, who were greeted by an enormous Brody 2012 fictional campaign poster, were the entire "Homeland" cast, including outstanding actress and actor in a drama series Emmy winners Danes and Lewis.
Also in attendance were Vogue Editor-in-Chief Anna Wintour and designer Valentino. Cocktails were followed by a screening of the first episode of season two and an after-party on the USS Intrepid flight deck complete with fireworks, tiny cupcakes in the "Homeland" logo and empanadas and pulled pork sliders served up directly under the Space Shuttle Enterprise.
Patinkin shared with CNN how he prepared for the role of Saul Berenson, CIA Middle East Division chief and mentor to Carrie. He traveled to Langley, Virginia, and met with a man who had been a CIA chief.
"I was asking a lot of emotional questions," the actor said, "because I was interested in his emotional reaction to certain situations, fears -- human nature questions."
At one point, Patinkin continued, the former CIA chief mentioned that he had two daughters, "and the daughters came over and then we were there for hours talking as a family, and that's when the nickel dropped for me. Before we shot a single frame, I realized it was a show about family. It was a show about Saul's relationship with his 'daughter' Carrie, the Brody family, the family of the CIA and the family of the world at large. And so that moment when those daughters came to that table -- I was home free."
Actor David Harewood plays David Estes, Carrie's boss at the CIA. He recalled meeting a CIA agent in preparation for his role as director of the CIA Counterterrorism Center.
"I happened to meet with a CIA operative who was a very scary lady," he said, "a very beautiful lady, but a very scary lady. I had dinner with her and she kind of looked straight through me. I felt like she was looking into my soul."
Harewood said he believes there has been such a massive positive response to "Homeland" from audiences because it is "one of the few shows which really seeks to not only entertain but also tell the truth. It really hit a raw nerve with people. People really want to know what goes on behind the doors of the CIA in terms of terrorists and terrorism, and 'Homeland' kind of seems to answer some of those questions."
Actress Amy Hargreaves plays Carrie's sister and caretaker Maggie.
"As season two opens," said Hargreaves, "it's six months later, so Carrie's had time to kind of go through some treatments and that's where we jump off. She's in good hands and we're kind of helping her regroup."
"What's nice about the way Showtime treats 'Homeland,'" Hargreaves continued, "is they give us time before we shoot every scene. We sit down, we talk about it, we figure out what feels right, what doesn't feel right. Working with Mandy is especially excellent ... we spent a lot of time on-set making sure that things were appropriate and accurate before we shot. It's been such a thrill to go to work and to get to work with Claire and Mandy. They blow me away."
Actress Morena Baccarin said "season two tops season one, if that is possible."
Of her character, Brody's wife Jessica, Baccarin said that she loves that "she's a no-frills kind of woman. She held her family together. She must have a sense of humor and strength somewhere deep inside that we don't get to see very often. The strength you get to see, absolutely, but she's vulnerable and going through a lot all the time, so you don't get to see her laughing very much. But this is a woman who held it together for eight years alone, so I think she's not a victim and she's not afraid; and when she is afraid she holds it together for her kids."
As for actor Diego Klattenhoff, who plays Mike -- Brody's Marine buddy and the man who became Jessica's love interest after she believed him dead -- he said that in season two, "I'm always there as his friend, kind of like a safety net. I'm always going to be there for the family. I think that inevitably I get pulled into certain situations."
Actress Morgan Saylor, who plays 16-year-old Dana Brody, said, "I love getting to be a hooligan and getting to be rebellious and openly so disdainful of my mother. That's really fun."
As for the upcoming season, of which eight out of 12 episodes have been filmed so far, Saylor said there are "definitely some changes this year between Dana and her father. She kind of sees his faults a little more."
We also spoke with musician Sean Callery, who wrote the "Homeland" theme song and writes the background score. He received his 12th Emmy nomination this year for "Outstanding Original Main Title Theme Music" for "Homeland." Callery was thrilled to be able to implement Carrie's love of jazz into the storyline in creative yet subtle ways.
"She's a spontaneous, improvisational character," said Callery, "impulsive. Not many shows have jazz, so it was nice to have something new."
"Homeland" is not a particularly heavily scored show. Callery said that if the audience notices the music too much, "then I'm getting in the way." But when it does contain music, Callery explained, "it's extremely transparent and very much in your face." For example, the pilot episode contains a scene that Callery wrote the music for, where a live jazz band is playing at a bar while news footage of Brody's return plays on TV screens. Carrie studies the musicians' finger movements on their instruments and concludes that Brody is tapping his fingers in some kind of code.
Callery, who won three Emmys for his work on Fox's "24," noted that "Homeland" die-hards will notice that the theme song has been varied ever so slightly for season two.
"It does evolve," he said. "It changes; it gets a little darker at times. I'm dying to speak of it but it hasn't aired yet."
Alex Gansa, series co-creator and executive producer, recalled finding out that "Homeland" was President Obama's favorite show.
"We didn't feel that we had to do anything different," Gansa said, "but it gives us extra impetus every day in the story room to try to make this thing good the second season, to try to live up to the promise of the first season."
Gansa said that the cast and crew remain stunned by the positive audience response to the program because "these wars that we're fighting overseas are so removed from the general citizenry and their consciousness that we were curious whether anybody would even be interested in watching, but one thing that we felt was missing from television was this idea of the returning soldier and so we really wanted to dramatize how difficult that return can be sometimes. And obviously there are some serious extenuating circumstances in Brody's case but if you watch the first series of episodes you could interpret Brody's behavior as either somebody who's hiding his terrorist motivations or somebody who's just having trouble re-integrating back into his life."