Sarah Carter has been sworn to secrecy.

She's hiding the details about the fifth — and final — season of the TNT sci-fi drama "Falling Skies." The last batch of new episodes have just begun rolling out.

All of the final episodes have been filmed, and Carter is careful not to share any details about how the series will end. After a little prodding, she finally says there will be some surprises and that "it ends in an extremely hopeful place." She gets a little cryptic when she adds that the last episodes will be "appropriate" and what fans are "not expecting."

For five seasons, fans have followed the story of the last survivors of an alien invasion of Earth. Rag-tag groups of rebels have come together to fight back. It's been a story of average people doing extraordinary things in the name of freedom. It's a sci-fi action series, but it never shies away from serious topics.

Carter plays freedom fighter Maggie. The cast also includes Noah Wyle, Connor Jessup, Moon Bloodgood, Maxim Knight and Colin Cunningham.

Carter got her start with a string of series-regular roles on "Undeclared," "Wolf Lake" and "Boston Legal." She's had work from being a member of the cast of "Shark" to a series of guest-starring roles on "Smallville" that continues to give her a huge fan base.

In high school, the Canadian actress was a member of the Royal Winnipeg Ballet and one of the top three public speakers in the world. Asked about those early accomplishments, Carter laughs, saying, "I was much smarter in high school."

She's smart enough to land jobs that have been both entertaining and challenging. The difference between her work on "Falling Skies" and other film and TV projects is how much she's been able to do with the role. Instead of one or, at best, a few episodes, Carter has had multiple seasons to develop the character.

"She's become a part of me," Carter says. "She has such a wonderful heart that has shown what it is to be brave and to love. I am proud of Maggie.

"What I appreciate the most about the show is that Maggie has been so complex and really developed. I loved the constant resistance — and capacity for love — that Maggie has. But she's always ready to fight the good fight."

Carter will miss more than just her character. She'll miss working with Drew Roy, who plays Hal Mason, because their characters spent a lot of time together. Carter calls it rare to get to connect with a cast and characters so deeply. And, while there was the serious business of making a television show, at the heart of the story was a ramped-up version of "Capture the Flag." That made for some fun moments on the set.

Before you start getting misty-eyed for Carter, she already has another television job. She plays a DEA agent on the DirecTV series "Rogue." The third season of the series, which also stars Thandie Newton and Cole Hauser, began last week.

The new series helps, but it is still tough on Carter to see "Falling Skies" end.

"It has been so well written. I will miss the huge sets," Carter says. "But, it's also time for it to end. Plus, actors start craving different stories and become anxious to try something new."