Jessica Chastain, James McAvoy on "The Disappearance of Eleanor Rigby"

First came "Him," then came "Her," and now comes "Them."

Jessica Chastain and James McAvoy are starring in the new romantic drama "The Disappearance of Eleanor Rigby: Them," the third and final entry in a trilogy of films about a married couple living in New York.

"Him" and "Her" were both released in 2013 to rave reviews, which prompted newcomer writer/director Ned Benson to put together an unplanned third film, "Them," focusing on the couple as they try to mend their relationship following a major event.

"It's when you love someone so much but you don't know how to communicate with them or fix them," Chastain explained to CBS News in a recent interview.

McAvoy said he was drawn to the project by the questions the story poses.

"Can you change as a couple and some people, some couples can't, and it's just really really hard to not believe that love endures then," the "X-Men: Days of Future Past" star said.

Watch the video above to see the actors describe what is like working together on set.

Chastain can also be seen in a new interview airing this weekend on "CBS Sunday Morning."

"The Disappearance of Eleanor Rigby: Them" is now playing in select theaters.