Jane Seymour and Tony Dovolani, <EM>Dancing with the Stars</EM> Jane Seymour and Tony Dovolani, Dancing with the Stars

Every Monday and Tuesday night, Dancing with the Stars' head costume designer stands at the back of the studio audience waiting for the show to begin. It's his reward to himself for making it through another grueling week. He needs to see his staff's original creations come to life as the stars and pros enter the ballroom down the twin twinkling staircases. Conception, design, manufacture and fitting of these highly technical dance garments all happen in the space of five short days. Major adjustments happen within hours of the show. The colors, fabrics, feathers and Swarovski crystals all have to be just right. "I have to be here," says Randall Christensen. "It's like watching my babies being born."

But on this Monday night, he's already seen something that took his breath away: Jane Seymour, in dress rehearsal, performing the tango. "She is a phenomenal professional," says Christensen, who designed her dress working in concert with Seymour's assistant. Seymour, who just lost her mother a week ago, has been away in England attending the funeral and, at the same time, somehow preparing to dance again. "She's exhausted, jet lagged and emotionally tired," says Christensen. "But when you saw that dress rehearsal? You would never know. She looked great when she was out there performing."

There was a lot of pain — emotional and physical — coming to the surface on Monday night. Two-time Indy 500 race driver Helio Castroneves hurt his foot and his knee on Wednesday and limped out of the ballroom. "I'm taped up everywhere," says Castroneves, showing off thick Ace bandages under his tux.

Billionaire Mark Cuban, who has become this season's Incredible Shrinking Celebrity, with a weight loss so far of 25 pounds, says the jive was a wicked test of an artificial hip that was installed at the end of June. "This is the first dance that actually made me nervous," says Cuban, who plans to spend Tuesday icing and resting. "There were moments when it was really bad. I mean, I'm OK now because the adrenaline's still flowing, but I'll be in pain tomorrow." His pro partner, Kym Johnson, is obviously concerned. "I was really worried about the jive," says Johnson. "Because it's such a demanding dance. And if Mark does too much, he might end up back in surgery and have to have the hip replaced again." How does Cuban's doctor feel about his recovery? "I won't let my doctors watch the show," says Cuban, who spends 30 minutes every morning in physical therapy, stretching, before beginning six long hours of rehearsal every day with Johnson.

Don't think the pros are immune to injury. Johnson says she was in Dallas last week when she ended up on the Dallas Mavericks' training table getting her ankle looked at. Cuban owns the team. "He's the one with the hip replacement, and I was the one sitting on that table," says Johnson, laughing. "I did something to my ankle and it was all swollen. I think I had a little bit of tendonitis. So Casey, the trainer for the Mavericks, helped me out."

Cuban loved it, because it offered a welcome diversion for his team. "All these guys come in from practice, walk into the locker room, and there's Kym laying on the training table!" Cuban says he has profound respect for the women who ballroom dance in heels. "I can't even imagine the pain that she's in," he says. "I couldn't do this in heels. A lot of times, during practice, she'll say, 'I have to take these off.'"

Marie Osmond is another celebrity who won't let pain be her master. But don't think it's not there. When Osmond performed the big finish to her tango, with her right leg pointed straight to the sky, she said, "This dance is a labor of love and I need an epidural," laughing. After the show, she's thinking about another medication. "Ibuprofen is a beautiful thing." For Osmond, it's all about soldiering through, conquering what she calls "getting stale." Then she smiles. "I gave it everything I had."

But there was wonderful pain relief for Jennie Garth, who attacked the dance floor as if she were beating a sworn enemy. Garth and her pro partner, Derek Hough, took a spill at the end of their lovely routine the week before. Garth was mortified. "There were so many times during the week when I just didn't want to dance," she says. "The frustration and the anxiety, I was really freaked out and overwhelmed. I just wanted to go home and hide in my bed and be with my children and not come out." But when she mastered the tango and got a standing ovation, the strain disappeared from her face. "I pounded it out," says Garth. "It was a true test of my character."

Take a twirl around the dance floor with Dancing with the Stars clips in our Online Video Guide.

Check out our exclusive interview with Bionic Woman's Michelle Ryan in the Oct. 8 issue of TV Guide. Plus: Get the inside scoop on the Sex and the City movie. Try four risk-free issues now!

Send your comments on this feature to online_insider@tvguide.com.