Is Rebecca out to mess with Karen’s head? Find out in Smash “Publicity.”

Smash “Publicity” Season 1 Episode 12 airs April 23 on NBC (10-11:00 p.m. ET) only on NBC.

Smash “Publicity” Synopsis / Summary: 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? 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. (Smash Episode Guide)