School improvement efforts rely on teachers' capacity for professional development and learning. We investigate the kind of roles taken by early career teachers (ECTs) with a master's degree from a research-based teacher education programme in relation to professional learning and school development in Norwegian schools after five years in the profession. The conceptual framework includes research of professional learning and trust. Semi-structured interviews of 26 ECTs were analysed using reflective thematic analysis. The findings illustrate four different roles that ECTs take: creators, translators, drivers and passengers. All the ECTs become creators, as they were enquiry-oriented and collaborated with colleagues to promote bottom-up professional learning, in order to improve teaching. Translators capture the ECTs' ability to translate a new curriculum into deep-learning and student-active teaching. Drivers obtain formal positions and promote professional learning in schools. Passengers take a passive role, and they are critical of the school system that introduces and performs a high number of top-down school-development projects. We discuss how ECTs want to develop relational trust, while the system may strengthen relational and structural trust.