Not all brothers and sisters get along. But when the sister's an actress and the brother sits in the director's chair, there's no place for sibling rivalry.

On this October day at the Manhattan Beach, Calif., sets of the NBC drama "Medium," star Patricia Arquette is fortunately having no trouble taking direction from her brother, David Arquette (also an actor, producer and writer).

"I like working with David," she says, taking a break outside in the sunshine. "He doesn't have the full script yet, so that's not a great advantage. It's funny, sometimes when he directs me, I'll think of something, and then he'll come and give me that direction that I just thought of.

"I was just joking, 'Don't mind-meld with me, David.' But he often has more interesting ideas than I do. I think I allow myself to be directed by him more than anyone else. I feel really safe with him."

That's a good thing, since the episode he's directing, "Do You Hear What I Hear," airing Monday, Feb. 18, is unusual. In it, spirit medium Allison Dubois (Patricia Arquette) psychically bonds with a missing girl. And because the girl is deaf, it has an unexpected effect on Allison.

"She loses her hearing," say Arquette, sitting at the Dubois family dining table, "so it's pretty intense."

As she often does in the show, Allison wakes up from a dream vision, but, David says, "I was able to shoot it upside down, because we wanted to disorient the audience. As she gets up, we kind of straighten out with her, but it's a way to completely do a new way of waking up, doing it in a way that disorients the audience, because she's disoriented by the fact that she can't hear."

As fans know, Allison is also a wife and mother. In one scene, she is washing dishes in the kitchen while one of her daughters tries to get her attention before being taken away by an older sister.

"You overcome it," Patricia says, "when you have a conversation and say, 'Listen, I'm still your mom. I can't hear; but I can feel. I can read to you. My voice works, my eyes work, and my heart works. I'm always going to be your mom. You don't have to take on all this additional responsibility, because I'm still here to do that. We might have to do things a little bit differently, but that's OK.'"

It's that family aspect that has always distinguished "Medium" from other shows about psychic powers.

"Everything I've done -- and it's not by design, it just works out that way -- seems to have something to do with the business of being men and women and all that stuff," says creator Glenn Gordon Caron.

"It always interests me, so I take great pride when people say they like that, because maybe we're doing something right."

Speaking of family, there are additional acting Arquette siblings: Richmond, Alexis and Rosanna.

"We've always been the secret agents of acting," Patricia says. "We've always flown low, struck suddenly and darted back. We're superspies like that."

"I have a project that I'm working on," David says, "that I'm writing, that involves the family."