Fabula is an experimental AI-powered co-creation tool developed by Google DeepMind to support writers in structuring, developing, and refining stories through an interactive and iterative process. Rather than acting as a traditional story generator, Fabula is designed to assist human creativity by helping users review, revise, and explore different versions of a story plan and script while maintaining full authorial control. It uses principles from classical narratology to guide the construction of narrative structure, enabling writers to build coherent plots, develop characters, and shape story arcs with AI-assisted suggestions. It allows users to navigate multiple levels of storytelling detail, from high-level plot outlines to more granular elements, making it adaptable to different writing styles, whether improvisational or highly structured. Powered by advanced language models, the tool generates coherent suggestions that help writers iterate on ideas.