BY DONNA FREYDKIN

It was the voicemail (not) heard around the world.

Or rather, the one never heard by Alicia Florrick, left by the now-dead Will Gardner (Josh Charles) telling her he loved her and he'd drop anything for her. Eli Gold (Alan Cumming) deleted it, so Alicia would stay with her straying husband (Chris Noth) and be part of his political future. Eli finally confessed to Alicia, and her response was a fearsome blend of rage and sorrow and a deep emotional shutdown.

It's part and parcel of the machinations, emotional, political and legal, on CBS' "The Good Wife," which returns this Sunday with another whopper of an episode, from one of the strongest writing teams on primetime.

"The writers gave me a synopsis of the second half of the season. I don't want to give anything way. They're gearing towards Alicia kind of having a nervous breakdown. In order to do that, they had to get to that phone call that's been haunting Eli all these years," says Margulies. "For me this season has been the most challenging. She's finding out about herself. The beauty that comes with age is this no-(expletive) meter. It's much more fun to play someone who doesn't care."

Margulies is pleasantly surprised by the reaction to that last episode. "I don't read any of that stuff. I'm not on social media. So I love hearing (expletive) like that," she says. "I don't do social media and I don't read anything. There's always going to be something negative. I went to see a play with John Hickey last night and we were both saying that the only review you remember is the one bad one. Why put yourself out there in that? Why not participate in life and see where the road takes you?"

One of the most heartbreaking moments on the show is the tease of an alternate life, one in which Alicia, had she heard that voicemail, might have left her husband and embarked on a relationship with Will -- one that might have led to a semblance of happiness. Does Margulies herself believe in chance? Absolutely.

"When I was doing a play on 45th Street, and I live down in Soho, I would walk every day. I put classical music on and I would go where the lights took me. That's why I love living in New York. You see something. It's something that affects you," she says. "Life is random."

As for Alicia, don't look for her to be swept up by romance. "She'll definitely find moments of happiness. I'm much happier than her," says Margulies, who's married with one son.

Margulies was also one of more than 100 luminaries to sign the #ENOUGH letter, thanking President Obama for taking executive action on gun control.

"I think about it every day. It's not just when I hear about another mass shooting," says Margulies. "I'll be riding the subway with my kid and I'll think, 'At any moment, someone could pull out a gun and it would be normal and it would be another headline.'"