"Homeland" season 5 is taking its lead character Carrie Mathison (played by Claire Danes) right smack at Berlin, where the former CIA operative is quietly working in private security for a German philantropist.

The setting is a huge shift from where season 4 left off, with Carrie back in her idyllic hometown in Maryland, America and possibly starting a romance with fellow agent Quinn.

But the "Homeland" team decided to place Carrie in "the great spy town" with "Russia banging next door" after their annual research visit in Washington D.C.

"If you'll recall what was happening at the start of the year, the whole Edward Snowden thing was really snowballing, the rise of Isis was happening, then there were the Charlie Hebdo attacks in Paris," executive producer Alex Gansa told Radio Times. "It all felt that now that part of Europe was the centre of the world."

With Carrie in Berlin, they are able to take a peek into the West and East and "concern about Putin rattling the sabre" would definitely play a huge part in the upcoming season.

Aside from that, the brains behind "Homeland" cannot deny the current threat posed by the Islamic State of Iraq and Syria (ISIS). They contemplated for a bit if they should incorporate them into the "Homeland" storyline, and in the end, they decided to push through with it.

"It has been difficult even to do the research required to portray that jihadist movement and dramatise it," explained Gansa. "Should we even acknowledge their existence, make them part of the story, and humanise them at some level?"

After getting the American-Russian narrative arc down pat, the team then decided the threat of ISIS is "just so part of the landscape right now that it felt like we were wilfully ignoring something that couldn't be ignored. So it has crept back into the story in a major way."

Try as she might to leave the CIA behind, the world of secrets and high-voltage espionage just can't seem to let Carrie go.

In a trailer for the next season, her former mentor Saul is trying to convince Carrie to come back to the life she has left behind.

"You've turned your back on your entire life," Saul said. "What are you atoning for? Keeping America safe? You're being naive and stupid, something you never were before."

"I'm not atoning. I'm just trying to do good work," Carrie answered back.