The Big C-cret is about to come out.

On season two of this Showtime drama, Cathy reveals her diagnosis to all around her, an announcement creator Darlene Hunt tells TV Guide was liberating to write:

"It's been a fun direction to go in since she was a little bit in denial the first season... Obviously, Cathy is the same person, but she's being faced with things that she never thought she'd be faced with, so it's fun to see her grow and change."

Look for the admission to bring Cathy closer to Paul and others, but there's one relationship that will be in danger once the disease is revealed: that of Cathy and her brother.

"We saw them come together a lot last year, but Sean finding out that news is going to threaten that closeness and then we might have to work to get them back together," Hunt says. "We really need to explore what his reaction will be because he was the one person she was the most concerned about telling."

Remember how Sean reacted to the news on "Two for the Road" last year, prior to Cathy taking it back?

The Big C premieres season two tonight. Return to TV Fanatic as soon as the episode concludes for a thorough review.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.