"Bombshell" is the fifteenth episode and first season finale of the American television series, Smash. The episode was written by series creator Theresa Rebeck and directed by Michael Morris. It premiered on the NBC network on May 14, 2012. In "Bombshell", Derek (Jack Davenport) has to choose Rebecca Duvall's (Uma Thurman) replacement in time for the show's opening night. The decision changes both Ivy (Megan Hilty) and Karen's (Katharine McPhee) lives forever.