Ben and Milly Dixon are being stalked by Kate Brown in their small town of Monaldo in south-east Queensland, Australia. Kate had been a girlfriend of Ben's, growing up with him in Monaldo and expecting marriage. But Ben opts for life as a reporter in Brisbane and meets and marries Milly, a fellow reporter. Eventually they and their three children move to Monaldo, where Ben takes over the family cattle property. Kate follows them. She is now so obsessed as to be mentally ill and is a lesbian, enamoured of Milly and seeking revenge on Ben for his betrayal. She is unrelenting, stalking them even on vacation and trying to kill their eldest son in what was deemed a road accident. The family gains some respite when called to Melbourne after the death of Milly's wealthy father. They have to sort out Milly's big inheritance but Milly is quickly celebrated in Melbourne for her beauty and wealth. She revels in the attention and drifts away from Ben, leaving the work on the inheritance totally to him and eventually treating him as a servant or employee. Ben rebels and leaves for home, threatening divorce. Milly, suddenly aware what she's done, chases him to the airport and physically stops him from boarding his plane, surrendering all control to him. Ben introduces tough measures to bring Milly back to earth and once again they're estranged but Ben persists and they soon are reconciled. They can now return home, but Kate awaits, out of sight but threatening. Soon after their return their daughter Mim 6 is missing from her bed and there is blood. The police mount a search but quickly give up, believing Mim is dead and will be impossible to find in the vast area. Ben and Milly know that Kate has Mim at the Wreck Lagoon, a beauty spot in the mountains on the edge of their property. Kate is a vet and has killed their watchdogs with strychnine darts, a weapon Ben greatly fears. He sets off on his horse with a rifle and an old pistol. He knows that Kate is waiting to kill him but is sure he can outwit her with his knowledge of the country and his bushman's skills...
