In the academic ranks of schooling, writing tasks move gradually from a focus on the transmission of knowledge to the transformation of knowledge. As a more complex writing task, knowledge-transforming requires writers to engage in the rhetorical act of persuading readers of their work's value, significance, and credibility. At the postgraduate level, writers may be wrestling with these issues for the first time, often discovering this more occluded rhetorical dimension only after they have become somewhat more comfortable with issues of generic form or subject-matter content. This paper explores the nature and role of rhetorical knowledge in advanced academic literacy through the writing of two multilingual writers. As these writers engage in high-stakes writing tasks, their rhetorical knowledge of disciplinary writing becomes more explicit and more sophisticated, influenced by mentoring, disciplinary participation, individual identity, and task exigency.