In this story, Dominic and his friends are part of a band preparing for a big performance at the Battle of the Bands competition. Dominic's younger sister Brandy blackmails him into letting her join the band as the lead singer after discovering his bad grades. Dominic allows it, but her presence causes chaos, as Brandy starts taking over and making changes to the band that nobody likes. Dominic's friends threaten to leave the band, but the siblings can't find a way out of the mess because of Brandy's blackmail.

Eventually, during the Battle of the Bands, things fall apart when the performance goes badly, and Dominic and Brandy's deception comes to light in front of their mom. Both siblings realize their mistakes and apologize, but their mom grounds them. However, she lets them perform one last time at the event. Brandy decides to leave the band and start a solo career, but the situation takes a humorous turn when their mom insists on filling in as the lead singer for the performance, leaving Dominic embarrassed.

The story highlights themes of sibling rivalry, consequences of dishonesty, and the importance of teamwork and accountability.