The present study was designed to understand the retrospective account of the learning experience of four successful learners of Russian who made substantial oral gains as measured by the ACTFL Oral Proficiency Interview (OPI) during a semester study abroad (SA) program in Moscow, Russia. Each participant made as much as two sublevels' improvement on the ACTFL scale, even those who began with Advanced level proficiency. Specifically, the study examines what students believe, how they exercise their agency, cope with constraints, and take advantage of affordances in out-of-class contexts. The qualitative data includes semi-structured interviews while quantitative data consists of pre- and post-program OPI scores. This research addresses the question of second language learning in a foreign language immersion program through thick description and through cross-case analyses. Findings were interpreted in relation to van Lier's theory of the ecology of language learning (2004) and the notion of affordances which suggests that if learners are proactive and outgoing (or initiate interactions) they will perceive language affordances as valuable and will use them. This theoretical approach provides a means to understand how most students were able to improve in oral performance while lacking meaningful contact with native speakers (NSs) or struggling to make friends with them. Regardless of the difficulties encountered during their time in Russia, students exercised their agency through participating in more self-initiated non-interactive activities without being directed by others. Each of the students perceived the meaning of his or her learning experience in a different way, demonstrating how the SA experience is highly individualized. This study argues that regardless of students' individual differences, they have one key principle in common: autonomous behavior. Further research is needed to investigate what fosters learners' autonomy and contributes to learners' self-efficacy.