A brief synopsis of the episode, courtesy of NBC, follows. Be forewarned, there are spoilers in the description. "Bombshell is turned upside-down by the arrival of movie star Rebecca Duvall (special guest star Uma Thurman)," according to press notes. "Karen (Katharine McPhee) and Ivy (Megan Hilty) are drawn into an uneasy alliance against their new rival -- but can they overcome their history? The romance between Tom (Christian Borle) and Sam (Leslie Odom, Jr.) heats up, while Julia (Debra Messing) and Frank (Brian D'Arcy James) must put aside their differences to address a family crisis. Dev (Raza Jaffrey) faces a big decision." Anjelica Huston and Jack Davenport also star.

As previously reported, the April 9 episode is titled "Understudy" and is described as such: "The show has landed a star, the mercurial Rebecca Duvall (guest star Uma Thurman), but Eileen (Anjelica Huston) is thrown into a panic when Rebecca gets stuck in Cuba. Derek (Jack Davenport) puts Karen (Katharine McPhee) in as understudy, but she must learn to perform under extreme pressure as he threatens to break her will. Tom and Julia (Christian Borle and Debra Messing) celebrate their anniversary with a ritual – and face some hard truths about what show business can do to relationships."

For more information visit www.nbc.com/smash.