Abstract The storyworld presented in the 2023 fantasy-comedy film Barbie is predicated upon a simple ontological binary: there is the Real World, in which humans reside, and Barbie Land, populated by plastic dolls, and it is roundly accepted that “never the twain shall cross”. However, throughout the film this divide is problematised, as the two domains impinge upon one another so consistently that Barbie herself recognises that “[t]he twain is crossing”. In this article, we explore the complex ontological structure underlying the Barbie film. A multimodal stylistic approach is adopted, and combined with insights from possible worlds theory, in order to investigate the linguistic, structural and visual features which present permeable and liminal spaces and occasion incidences of ontolepsis. Ultimately, the analysis serves to illuminate Barbie’s playful approach to multiple, interwoven, and overlapping ontological levels — be they in Barbie Land, the Real World, or even our own real world.