This paper revisited the issue of transfer in an unexplored context: the transition from instruction-based writing to the bachelor's theses by English-major students in one university in China. To explore the extent to which the writing instruction prepared the students for thesis writing practice, we created two corpora of student writing: 591 assignments produced by 40 students in 3 writing-related courses offered in the curriculum and 40 bachelor's theses produced between 2014-2018. Based on the taxonomy of elemental genres in the Systemic Functional Linguistics, we compared the genre distribution in the two corpora via log-likelihood tests. Results revealed that two patterns of "continuity" and two patterns of "discontinuity" existed in the students' literacy journey. Also, framed within the theory of adaptive transfer, a focus-group interview was conducted with four thesis writers in an attempt to trace their transfer of rhetorical knowledge between the two rhetorical contexts. Findings demonstrated that the students consciously "reused" and "reshaped" a pool of rhetorical knowledge acquired from the writing courses to navigate the complex task of thesis writing. This paper then concludes with implications for L2 writing research, curriculum, and pedagogy.