Parallel Forces is the story of a unique family, centred on Amyrra, one of twin sisters. Amyrra's story is set mainly in modern Australia but also in ancient Java. Her life parallels the life of a queen, Ken Dedes, in the Golden Age of a Javanese kingdom. Amyrra seeks refuge in a personal God to free herself from her fate to love and suffer again, as she believes she had so many centuries earlier.

The story opens with the adult sisters attending a wedding in suburban Camberwell, then quickly flashes back to childhood in Singapore. They were born in Singapore, where their Javanese father, Hardoyo, a poet and their French mother, Claudine, an artist, lived for ten years.

Moving to Indonesia when the girls were just teen-age, the family is shocked when a village seer tells Amyrra that she is the present incarnation of the twelfth century Javanese queen, Ken Dedes, and that she will meet the present incarnation of the queen's lover, Ken Arok, and they will resume their love affair.

During the Golden Age of the Majapahit kingdom, Ken Dedes married her lover, Ken Arok, after he had killed her husband, the king. Their relationship ended unhappily and their descendants have fought and killed each other for generations after.

Despite her obsession to avoid meeting her fated lover, Amyrra finally meets Sean Devlin, who she feels she has known for a long time. From then on, her life parallels the life of Ken Dedes, as she is swept toward the horrifying end.