Volume Fourteen of the Holophase Science Programme examines prebiotic complex systems at the boundary between planetary habitability and life. It develops a rigorous framework for environmental ensembles, geochemical pathways, linked reactors, open reaction networks, compartment precursors, polymerisation, nonenzymatic copying, homochirality, cycling and abiotic niche structure. Throughout, the book keeps chemical organisation distinct from metabolism, heredity, Darwinian selection and life, and makes its evidence standards, uncertainties, rival explanations and falsifiers explicit.