Crystallization in liquids is a fundamental phase transition. While for many years, the understanding of crystallization was governed by classical nucleation theory, recent research has shifted focus to non-classical pathways in crystallization. In a new study, scientists from the Institute of Industrial Science, The University of Tokyo, reveal that the crystal precursor structure, which forms spontaneously as a structural fluctuation in a supercooled liquid, has a critical impact on crystal nucleation and growth.