Eminent scientists, like Einstein, worked with theoretical contradiction, thought experiments, mental models and visualisation--all characteristics of children's play. Supporting children's play is a strength of early childhood teachers. Promising research shows a link between imagination in science and imagination in play. A case study of 3 preschool teachers and 26 children (3.6-5.9 years; mean age of 4.6 years) over 6 weeks was undertaken, generating 59.6 h of digital observations and 788 photographs of play practices. The research sought to understand (1) how imaginative play promotes scientific learning and (2) examined how teachers engaged children in scientific play. Although play pedagogy is a strength of early childhood teachers, it was found that transforming imaginary situations into scientific narratives requires different pedagogical characteristics. The study found that the building of collective scientific narratives alongside of discourses of wondering were key determinants of science learning in play-based settings. Specifically, the pedagogical principles of using a cultural device that mirrors the science experiences, creating imaginary scientific situations, collectively building scientific problem situations, and imagining the relations between observable contexts and non-observable concepts, changed everyday practices into a scientific narrative and engagement. It is argued that these unique pedagogical characteristics promote scientific narratives in play-based settings. An approach, named as "Scientific Playworlds," is presented as a possible model for teaching science in play-based settings.