Janie Jones is a 13-year-old amateur musician who arrives at a show with her meth-addicted former-groupie mother, Mary Ann Jones. The performance is by Ethan Brand, an alcoholic, on-the-road fading rock star who, unknown to him, is Janie’s biological father. Mary Ann had previously been a groupie for Ethan’s band. She informs him of Janie’s birth and pleads for him to step in, while she enters rehab. Ethan recognizes Mary Ann but pretends not to know her and sends her away. During the show, Mary Ann abandons Janie, leaving her devastated and calling the police. With Mary Ann missing and Janie’s phones shut off, Officer Dickerson brings Ethan and his girlfriend Iris into the loop. Because Mary Ann’s drug possession arrest and Ethan’s name on the birth certificate could mark him as a “Deadbeat Dad” if Janie ends up in state care, he faces potential legal trouble—a fate he can dodge only by taking Janie on tour. He reluctantly agrees, though Mary Ann’s reappearance soon complicates things for Iris.
On the road, Janie meets Ethan’s band—lead guitarist Billy, drummer Chuck, bassist Dave, and manager Sloan. The musicians feel uneasy around Janie, except Sloan, who offers quiet support. Tensions rise as Janie’s presence and Ethan’s unpredictable behavior intrude on the tour. When Ethan learns Iris has been cheating on him with Billy, he drunkenly broadcasts the accusation to a show’s crowd, sparking a fight and prompting the band to walk off stage.
Iris returns to Los Angeles after the breakup, and the rest of the group scolds Ethan for his recklessness. Back at a motel, Sloan shows him a video of the brawl that’s posted online, and a furious Ethan declares that Janie needs to go. Janie overhears and sinks into despair. The band continues performing with Janie by Ethan’s side, and his drinking only worsens. The duo begins to form a real connection when Janie strums a stirring rendition of House of the Rising Sun for the audience. Frustrated, the other band members decide to quit, and Chuck even delivers a punch when Ethan tries to stop them.
With the band gone, Ethan resumes the tour solo. Sloan returns to Chicago while Janie travels with him in a used car, and a genuine bond grows between them. During a show, Ethan receives little attention, triggering a scuffle that Janie defuses by performing her own song, impressing the crowd and the venue owner. The owner offers to sign a father–daughter act, and Ethan reluctantly agrees, much to Janie’s happiness.
As they build momentum, Ethan’s alcoholism continues to cast a shadow. At a later show, his intoxication leads him to lash out at a man who makes crude remarks about Janie, and he is arrested. Unable to enlist Sloan’s help, Janie pawns their equipment to bail him out. They share a tearful reconciliation, but without the money to reclaim their gear, Ethan seeks help from his estranged mother, Lily. She is initially appalled by his lifestyle and skeptical about Janie’s paternity, but Ethan’s candid admission finally convinces her, and she lends them money.
Back on the road, Ethan and Janie talk about how he met Mary Ann and about his father’s suicide when he was nine. They use Lily’s money to buy back the equipment. Mary Ann calls to say she’s out of rehab and back home, and Ethan discovers she and her boyfriend have been clean for a month. He apologizes for not being there as a father and for how Janie changed his life. Wishing to stay close to Janie, he asks her to join him on tour, and she happily agrees.
Sometime later, Ethan and Janie perform as a father–daughter duo in front of a large crowd, marking a new chapter in their lives as they complete a journey that began with a complicated arrangement and grew into a renewed sense of family and purpose.
