Los Angeles auto magnate James Belmont marries single mother Catherine Sullivan, and straight-A student Grace Sullivan moves into the mansion, becoming the stepsister of rebellious motorcycle-riding teenager Jett Belmont. Jett Belmont despises the blended family and takes out his frustration on his new relatives, constantly ignoring Grace Sullivan. He has no idea that Grace Sullivan is the little girl he saved at the scene of a car accident years ago—a secret crush she has kept hidden since her teenage years. Living under the same roof, Grace Sullivan quietly resolves Jett Belmont’s school troubles and even takes the blame for his illegal street racing violations. Jett Belmont’s icy facade begins to thaw, and the two grow closer, but due to Los Angeles high society’s zero-tolerance policy toward step-sibling relationships, neither dares to cross the line. That is, until Brian Thorne, a wealthy Ivy League fraternity member, sets his sights on Grace Sullivan. Sensing the sparks between the siblings, Brian Thorne, consumed by jealousy, directly leveraged his family’s wealth to force Jett Belmont’s custom car shop—his lifeline—out of business with exorbitant rent hikes. To protect Grace Sullivan’s future at an elite university, Jett Belmont ruthlessly pushed her away, unilaterally drawing a line between them. Watching Jett Belmont’s life’s work on the verge of being crushed by corporate might, the once-model student completely lost her cool. She staked her Ivy League acceptance letter and stormed into the underground racetrack, issuing a challenge to Brian Thorne: her future in exchange for the survival of Jett Belmont’s shop. Amid the roar of engines, Grace Sullivan fought her way to victory in this life-or-death street race. Upon hearing the news, Jett Belmont lost all control, stormed onto the track, and overturned Brian Thorne’s bet. In front of every driver present, he yanked Grace Sullivan toward him and kissed her passionately. Flashbulbs and cheers erupted throughout the venue, while a video of that forbidden, passionate kiss was now playing on their parents’ phone screens. A storm powerful enough to upend both families had only just begun to rumble.
