Mark Seliger/NBC

"Smash's" Katharine McPhee and Megan Hilty

[Warning: This story contains spoilers from the season finale of Smash.]

NBC's Smash wrapped its freshman run Monday by crowning a Marilyn Monroe once and for all as Bombshell was forced to make a final decision between Ivy, who played the part during the workshop, and newcomer Karen, the show's most recent understudy.

Ultimately, Derek's (Jack Davenport) visions of Karen (Katharine McPhee) as Marilyn gave her the edge over Ivy (Megan Hilty), despite his romantic connection with the latter. His decision, meanwhile, doesn't go over well with Tom (Christian Borle), Julia (Debra Messing), Eileen (Anjelica Huston) and Ellis (Jamie Cepero), who admits to getting rid of Rebecca Duvall (Uma Thurman) so the production could make its way to Broadway.

"Derek keeps seeing her as Marilyn and that's hard when a director sees something -- even if no one else sees it -- there's nothing else that can change that person's mind," McPhee tells The Hollywood Reporter.

STORY: 'Smash' Finale Preview: Who is Best Equipped to Be Marilyn?

Karen's big break, however, doesn't come easy as she's tasked with not only learning the rewrites and last-minute changes but also contending with frenemy Ivy, who isn't happy about being bypassed for the part and confesses to sleeping with Karen's boyfriend, Dev (Raza Jaffrey), after his botched marriage proposal.

"She's paying for a lot of things that I don't think that she necessarily deserves," McPhee says. "Her boyfriend acts in disgusting ways and Ivy tries to redeem herself by being honest with what's happened, but she's despicable herself as well."

After confronting Ivy and Dev, Karen ditches both and, following a pep talk from Derek -- who points out that in addition to having Marilyn's desire now shares heartbreak with the icon -- returns to center stage with a newfound confidence.

Excerpt from:
'Smash' Finale Postmortem: A Marilyn is Crowned Once and for Good