Tonight’s fifth episode of NBC's hit show 'Smash,' titled 'Let's Be Bad,' started off with the minutes before the newest rehearsal of ‘Marilyn.' Director Derek (Jack Davenport) asks Karen (Katherine McPhee) to help him with a new dance number, sparking jealously in Ivy (Megan Hilty). Tensions also rise when Eileen (Anjelica Houston) demands new script pages from Tom (Christian Borle), and Julia’s (Debra Messing) former lover Michael (Will Chase) asks for help with his role of Joe DiMaggio in the musical. Everyone involved in the musical production of 'Marilyn' appears to be at their wit's end.

After rehearsal Michael and Julia have dessert, discussing DiMaggio’s relationship with Marilyn. Tom goes on a date with his new lawyer stud, John, but is distracted by work until Julia’s son Leo calls, saying he has been arrested.

Tom watches in awe as John argues on behalf of Julia’s son Leo at the police station. On the other side of New York City, Karen meets up with her boyfriend, but goes home alone when he is forced to work late with his attractive female coworker. Back at home, Julia is furious with her son for smoking marijuana in Central Park. Tom accuses her of walking a fine, flirtatious line by having dessert with Michael.

When Tom’s assistant Ellis delivers a book to Eileen, an alliance begins to form. At the next practice, Ivy sings a new song, but Derek cuts her off, asking Karen to show her how it’s done. Karen reluctantly sings her rendition of ‘Happy Birthday,’ sparking fury in Ivy.

Before the next practice, Ivy venomously tells Karen to watch herself while Julia receives a phone call that Leo’s police encounter may cost her family their chance of adopting a baby. During the rehearsal, Ivy’s confidence slips when her performance is not met with approval from Julia, Tom, Eileen and especially Derek.

The following day, Derek blows off Ivy’s attempt at a conversation at rehearsal and Tom subtly warns Michael to stay away from Julia. Due to nerves, Ivy continually messes up the routine and breaks down in tears. She gathers herself together and suddenly we are thrown into the musical world, where we see a performance of ‘Let’s Be Bad’ from ‘Marilyn.'

This is the first time we see an acting sequence accompanying music from the musical. There is a movie set on stage where directors and crew are complaining about Marilyn being late and threatening to firing her. When Marilyn does make an appearance she takes pills against the advice of her husband Arthur Miller and seems drugged up. During the performance Marilyn is being pulled apart by the cast and crew, berated by snide remarks and false compliments, and her insecurities are threatening to break her.

Back in reality, everyone (except Derek who storms out without a word), meets Ivy with grand applause. Because of this, she goes out drinking with a fellow cast mate and Michael to a bar.

At home in her apartment, Karen complains about her difficulties at work. Her boyfriend is unsympathetic, asking her to dress sexier than usual for his work dinner that night. She sings ‘It’s a Man’s World’ to attempt to get in touch with her sex appeal.

The same night Michael surprises Julia at home, much to the delight of Leo, who invites Michael to stay for dinner. Also making a surprise visit, Ivy shows up drunk at Derek’s apartment. Ivy accuses him of humiliating her at rehearsal. “I don’t exist to you,” she blames. Without emotion he responds, “Nobody exists in there.” Yet in his classic charm, Derek changes his rough demeanor, asking her to stay the night.

Karen shows up to the lavish work dinner in a sultry red gown. Channeling Marilyn, she flirts with the man sitting next to her and scores some beneficial work information for her boyfriend.

The summer night is warm as Michael and Julia wait for a car service. Michael confesses to wanting to be with her despite their families, and sings ‘A Song For You.’ Julia tearfully asks him to leave and he goes to the car. However, they exchange a longing glance and the two finally embrace in a passionate kiss. Viewing it all from a second floor bedroom … is Leo.

Stay tuned next week for the continued saga of 'Marilyn' on 'Smash' -- even though the real drama isn't even on the stage!