Data Journeys in the Sciences dismantles the fiction that data remain identical while moving between laboratories, databases, disciplines and political settings. Across its cases, data appear as relational achievements whose meaning and evidential force depend on packaging, cleaning, classification, standards, instruments, labour and institutional histories. The “journey” is both methodological device and theoretical proposition: tracing circulation reveals transformations concealed by the rhetoric of frictionless reuse. Movement does not merely transmit data; it produces new objects, exclusions and possibilities of inference. The volume’s comparative architecture makes epistemic diversity visible without treating every practice as incommensurable, since journeys can be studied through recurrent operations such as decontextualisation, recontextualisation, repair and validation. Its broader contribution is to replace the static archive with an infrastructural account of knowledge. Databases, formats and metadata become active environments that govern what can travel, who can interpret it and which histories remain attached to apparently neutral informational objects.