04/25/2012 10:01 am ET

Uma Thurman On 'Smash': 'Bombshell' Musical Problems As Rebecca Voices Fears (VIDEO)

Even movie stars have insecurities.

On the upcoming episode of "Smash," called "Tech" (Mon. April 30, 10 p.m. ET on NBC), the current "Bombshell" star Rebecca Duvall (Uma Thurman) isn't too thrilled by how things are going with the musical.

"Look, I know that everybody thinks I'm a joke," Rebecca tells Derek in the exclusive preview clip above. "Derek, you're having other people standing in for me."

To further those fears, she's been left in the dark about losing "Bombshell's" leading man. (Re-enter Michael Swift?)

But Derek (Jack Davenport) is quick with advice to calm the star. "You know, Marilyn was always afraid of being a joke," he says. "All that feeling of not being authentic, having something to prove ... Use it."

Check out the video above and read the full "Tech" episode description below.

"Bombshell" moves to Boston. Ivy (Megan Hilty) faces trouble as Derek (Jack Davenport) finds himself drawn ever closer to Rebecca Duvall (special guest Uma Thurman), while Karen (Katharine McPhee) reaches a turning point -- she must choose between Dev (Raza Jaffrey) and the show. Eileen (Anjelica Huston) faces off against Julia (Debra Messing) over the possible return of Michael Swift (Will Chase). Sam (Leslie Odom, Jr.) brings Tom (Christian Borle) into the biggest battle of all -- family dinner.