Dynamic shifts of language learners' willingness to communicate (WtC) have been investigated in a number of studies with a view to establishing the impact of various cognitive, affective, social and contextual factors. Looking into such influences in the context of a language classroom gives an opportunity to identify variables that might remain within the control of the teacher, thus contributing to creating optimal conditions for language development. The present study is an attempt to explore WtC fluctuations in the course of six lessons spanning the period of one semester of a single student who outperformed all other group members on a number of measures, but most importantly, on an oral test. The following data collection tools were used: (1) self-report WtC grids for every class, (2) detailed lesson plans, (3) an in-class WtC survey and (4) an interview. Qualitative and quantitative analysis of the data disclosed a network of personal and group-related factors that are capable of shaping communicative behaviour in the classroom.