Cat Cleary is a 16-year-old Irish 'slummy' arriving in Liverpool to seek her fortune. Joe Calligan thinks she's the loveliest girl he's ever seen. Cat sees the White Empress, a huge luxury liner. In that moment her ambition is born -- to be chief stewardess. In spite of her poverty and lack of education, Cat Cleary sets about realising her dream. While doing so she discovers that having a good man by her side will bring her even more happiness.