Kay Martin (Jessie Matthews) is sailing a barge down the River Thames. She dreams of becoming a star. The Skipper's son, Steve (Barry MacKay), is also on board and is constantly studying finance. Although the two are devoted to each other, they bicker and argue constantly. When Kay is spotted by a producer, Steve is reluctant to let her go. But she does, and is transformed into a great dancer and a perfect lady. She has London at her feet, including a producer who has fallen madly in love with her. Are she and Steve still destined to be together?