Mia's best friend, Lilly, flies to Genovia to help find a future husband. After non-stop searching, they settle on a Duke from another kingdom. To thwart this romance, Mabrey convinces Nicholas to woo Mia himself. Even though they argue, and Mia spends most of her time disparaging Nicholas, it is clear that they are falling for each other. Although they admit they are in love, a series of mishaps and unfortunate events masterminded by Viscount Mabrey leads Mia to believe that Nicholas has betrayed her. Because of this, she decides to go through with her wedding to the other Duke.
Nicholas learns Mabrey is behind the betrayal. He rushes to the wedding where he learns Mia couldn't make herself marry someone she doesn't love. Mia convinces the government to change the law so she is able to rule the kingdom without marrying. At her coronation ceremony, Nicholas confesses how much he loves her and the two, as they say, live happily ever after.