This embedded case study investigates the nature of authorship in a secondary English Language Arts classroom by examining two adolescents' writing identities and experiences writing across genres. Using rhetorical genre theory, the study illustrates how composition and notions of authorship in this context were strongly informed by conversations--both with peers and the teacher. An additional finding was that students wrote themselves into different genre identities as they composed poetry, editorials, and memoirs, drawing on different authorial stances and sources of knowledge. Finally, this analysis documents robust learning about the nature of writing, including transferring rhetorical strategies across contexts and purposes, skills often called for in education policy as well as career and college writing, not documented in secondary schools. Implications for teaching include valuing relationship-building conversations, offering students multiple genre positions across secondary writing experiences, and considering ways to build upon writers' self-described and socially constructed identities as successful writers.