After years spent as a widower, village doctor Mr Gibson has decided to remarry; something for which his rather naive daughter, Molly, is wholly unprepared. Molly's world is soon overturned by the arrival of an unwanted stepmother and a bewitching, beautiful stepsister, Cynthia.

In spite of the circumstances of their acquiantance and of being so entirely different from one another, the two girls instantly form a close relationship. But it is a friendship that is put to the test when they look set to become rivals in love. Matters are further complicated when a dangerous secret emerges from Cynthia's past in which she entangles Molly, with serious consequences for them both...