"We met with a number of former and current CIA agents, we read a lot of books, and we invented the rest," Gansa said. "We obviously wanted to be as true to life as we possibly could, but we would always err on the side of making the story more exciting and more thrilling."
They gunned for Danes from the start.
"We needed somebody by turns who could appear very confident and very unbalanced at the same time," Gansa said. "Claire was the first choice from the minute we started the character. We actually called the character Claire in the first couple of drafts."
Gansa said that aside from the 2010 HBO film "Temple Grandin," for which Danes won an Emmy, he and Gordon "just felt that she wasn't being served well by the projects she was involved in."
"We felt this was a chance for her to play something different," he said. "A real professional woman. Not the love interest, not the best friend -- a real strong, meaty, smart female character."
Danes declined to be interviewed for this story through her representative. She and the rest of "Homeland's" cast and crew have been busy: Over the past week, they've descended on Charlotte, N.C., for what will likely be a 15-day shoot for the season finale. That episode, "Homeland's" 13th, will be longer than the usual hour, clocking in at 80 to 85 minutes. They hope the pattern extends to the series.
"We're in that beautiful little bubble that people kind of dream of when you've just launched a show, the critics raved about it, people seem to be watching it, and you just get the sense that this is the best it can ever be," Lewis said. "You just hope that the bubble won't burst."