Garson Kanin's Broadway hit was transferred to the screen with only a few passing nods to the stricter censorship required by films. Judy Holliday won an Oscar for her portrayal of Billie Dawn, a strident, dim-bulbed ex-chorus girl who is the mistress of millionaire junk tycoon Harry Brock (Broderick Crawford).
In Washington to put a few senators and congressmen in his pocket (the better to lay the groundwork for an illegal cartel), the rude-and-crude Brock realizes that the unrefined Billie will prove an embarrassment. Thus he hires idealistic but impoverished Paul Verrell (William Holden) to pump some intelligence and class into Billie.
Paul does his job too well; by awakening Billie's social and political consciousness, he turns the girl into Brock's most formidable foe in his efforts to buy influence in DC. Along the way Paul and Billie fall in love.