One quiet night on Warratah Island, a reclusive man and his over bearing sister find their fragile domestic routine shattered when a mysterious stranger abruptly bursts into their home and refuses to leave. Introducing herself as Nancy Nancy, the intruder is controlling, unsettlingly maternal, and utterly unstoppable. Stripped of agency, the siblings are held hostage in their own house, forced to perform a series of increasingly bizarre and humiliating acts as Nancy Nancy bends them to her sadistic will. Submission becomes survival.

As Nancy Nancy spins contradictory stories of prison, murder, and a violent past, her true motives remain maddeningly unclear. Is she a fantasist, a psychopath, or something far worse? And why has she chosen them? When Nancy Nancy brings home an American lover, the final pieces fall into place—revealing a twisted power play where control, identity, and madness collide in a surreal, darkly comic nightmare.