Mary Hetherington dominates her family. She's runs a spotless house, and she's kind, efficient and generous - providing they do what she wants. But when her son brings home a girl from the 'wrong end' of the Fifteen Streets she soon takes against her. When she discovers that Sarah is loved not just by David but by all the men of the house, Mary realizes that the 'interloper', if allowed to go unchecked, will become a challenge to her authority. Meanwhile Sarah finds that even the most proper people have their quarrels, and secrets they're anxious to hide.