After returning from a fifteen-state tour, Mars brings her friend Karen into Lillie's Place, where she works as a sound girl. Karen is interested in Artie, the lead singer of Heroes, the band performing that night. Lillie, the bar owner, tells Mars that a new Seattle-based band named Noir is opening for Heroes.

The handsome lead singer of Noir takes the stage along with the rest of his band and their music is transformative. Mars walks over to the stage after the performance concludes to give the band's sound girl some tips. Behind her, Noir's lead singer thanks Mars for her help and introduces himself as Duncan Black. Mars offers to do sound work for their second set, and Lillie asks her why she's helping the band, since they can't afford her.

At the end of Heroes' set, Mars takes Karen to the green room and introduces her to Artie, the lead singer, and they hit it off. After listening to their CDs all night to prepare, Mars meets Noir at a restaurant the next day to discuss working together. She wonders if it's a good idea, given her attraction to Duncan, but she's always sworn she'd never hook up with a musician. She tells the band their sound is too clean. The musicians are resistant at first, but Duncan gives the final word, saying she's in.

Duncan is naturally flirty, but Mars stays strong and spends hours with the band, tweaking sound and suggesting changes to the music. Each show gets progressively better and Mars connects them with a recruiter named Jimmy who agrees to fund them and they form a touring team. Duncan goes into music-writing mode and speaks to no one. One day, one of the band members, Johnny, calls Mars and says they're ready to record. The new songs stun Mars and they work on getting them ready for audiences. After, they eat a midnight breakfast, she and Duncan have an intensely romantic interaction but they shut it down before it goes anywhere.

Jimmy books them at a packed stage and the band is nervous but they perform well. They depart for San Diego the following morning. On the road, Mars tells the band about how she lost her virginity in a threesome in high school. At a club, the Mars and Duncan dance with one another but they break it off when it becomes intense.

As they perform more, Duncan becomes moody and a player. Mars gets jealous and eventually they have a sexual encounter that she regrets when he immediately returns to his other girl. Their professional relationship strains, but when Duncan breaks down Mars is the only one who can set him straight before an important performance. On stage, Duncan talks directly to Mars, telling her that she terrifies him because of her intensity and the sincerity of her feelings for him. He tells her he loves her and in the green room after she reciprocates.