Celia Frost has always thought herself a cut above the residents of Lark Rise, Battersea. So when her beloved son, Thomas, starts seeing neighbour Amy Miller, Celia disapproves, thinking her common. When Celia's husband leaves her, and Thomas announces he is to marry Amy, she is more determined than ever to split them up. She writes to her eldest son Jeremy to come home. Jeremy's arrival unleashes a tide of jealousy and hate. He wants everything that belongs to Thomas - especially Amy. As Jeremy's dangerous obsession for his brother's wife grows, Amy must fight for her marriage, and her new baby.