Julia Houston and Tom Levitt, a Broadway writing team come up with the idea of a new musical based on the life of Marilyn Monroe, entitled Bombshell. Producer Eileen Rand, in the midst of divorce proceedings from her philandering husband, jumps on board and brings with her Derek Wills, a difficult but brilliant director.
Ivy Lynn is initially cast as Marilyn, but is forced to deal with competition from the talented, yet naive ensemble member Karen Cartwright. Julia’s former lover Michael Swift is initially cast in the role of Joe DiMaggio. However when Julia and Michael’s reunion causes serious trouble in her marriage to Frank, the decision is made to fire Michael.
The role of Marilyn is recast with film star Rebecca Duvall, leaving Ivy devastated. After a somewhat disastrous out-of-town opening in Boston, Rebecca is felled by a peanut allergy and the actor playing Joe departs the production for a better gig.
Derek subsequently casts Karen in the role of Marilyn and Michael is reinstated as Joe. Karen discovers Ivy has slept with her fiance Dev, while Eileen finds out that her assistant Ellis was the one who poisoned Rebecca and fires him. Karen gets through her debut and the season ends with the closing number being applauded by the audience.