Sisters Caroline and Isabella Foster are abused by their stepdad, Robert Sterling, while their mother, Diane Sullivan, remains oblivious. To pay his lover's debt, Robert attempts to sell Isabella. Caroline is hospitalized trying to save her. Later, Caroline witnesses a fleeing Isabella get critically injured in a car crash. Robert intercepts all of Caroline's desperate calls to Diane. Isabella tragically dies, leaving Caroline utterly disillusioned with her mother. Discovering Robert's affair, Caroline teams up with Simon Gallagher to expose him. Robert is brought to justice, and a remorseful Diane reconciles with Caroline.