A brief synopsis of the episode, courtesy of NBC, follows. Be forewarned, there are spoilers in the description.
"Karen (Katharine McPhee) finds herself seduced by the glamorous life of new BFF Rebecca Duvall (special guest star Uma Thurman) -- but can Rebecca be trusted?" ask press notes. "What will Karen's ascent mean to her relationship with Dev (Raza Jaffrey)? And will Rebecca drive Derek (Jack Davenport) insane? Eileen (Anjelica Huston) introduces new beau Nick (guest star Thorsten Kaye) to ex-husband Jerry (guest star Michael Cristofer), while Julia (Debra Messing) panics when her son Leo (Emory Cohen) goes missing." Megan Hilty and Christian Borle also star.
For more information visit www.nbc.com/smash.