In this study, we present the cases of two latecomers to college science who, unlike most latecomers in their program, successfully persisted to graduation. An analytic framework of figured worlds, cultural models, and identity work is employed to understand the challenges they faced. The dominant cultural models of learning that were reproduced in their science courses are explored through data drawn from lecture and laboratory observations, teacher and student interviews, and student journals. The analysis shows that the dominant teacher-centered and sink-or-swim cultural models of learning severely limited the available resources for latecomers' identity work. The resources that were available tended to afford recognition as good students, rather than as being good at, or interested in, science. However, by improvising with the available resources, including some acquired outside of the science program, the two latecomers were sometimes able to reposition themselves in more powerful subject positions, which had far-reaching consequences for their science trajectories. We also demonstrate how using a sociocultural framework and methodological approaches that focus on student-teacher interactions yields insights into the persistence of nontraditional students that are not possible when the focus of research is solely on learning and cognitive gains.