VIDEO: Sneak Peek - Katharine McPhee Sings 'Never Give All the Heart' on Next SMASH

Below, check out a sneak peek from next week's episode of NBC's SMASH. In the episode titled 'Fringe', with the future of Bombshell uncertain, Karen (Katharine McPhee) gives producers a taste of the all-new original song, "Never Give All the Heart."

Also in the episode, Derek (Jack Davenport) and Karen find themselves at a surprising crossroads, forcing one of them to make a difficult choice. Jerry's (guest star Michael Cristofer) uneasy partnership with Eileen (Anjelica Huston) hits a snag, as does "Hit List's" first performance at the Fringe Festival.

Meanwhile, Ivy's (Megan Hilty) last-ditch effort to save her and Terry's (guest star Sean Hayes) show has unexpected results. Debra Messing, Christian Borle, Jeremy Jordan, Andy Mientus and Krysta Rodriguez also star. Sean Hayes, Jesse L. Martin, Daniel Sunjata and Nikki Blonsky guest star. The episode airs Tuesday, March 12 at 10:00 pm/ET on NBC.