The significance of motivation in learning an additional language has long been recognized in the field of SLA. However, a few studies have investigated the role of motivation in the learning process of an individual, especially for the attainment of particular language skills such as the acquisition of reading aptitude in L2. On the other hand, considerable research investigates the contribution of motivation to the achievement of reading proficiency but only in the context of acquiring the first language. Therefore, this case study explores the ways learners perceive their motivation in the EAL/EFL context of Bangladesh as they strive to develop their English reading skills for academic purposes. To be precise, this study addresses the motivational orientations, reading behaviours, and reading achievements of post-secondary EAP students while their reading motivation is being constructed and reconstructed by their learning experience. For the purpose of the study, data has been collected over four weeks in the form of a series of open-ended individual interviews following the completion of motivation logs by the students while they continue their EAP course. The findings suggest that motivation is not a static phenomenon: Reading motivation of the L2 learners varies throughout their learning process by the continuous influence of their learning experience inherent in their micro-macro settings as different motivation orientations unfold themselves at different intervals and their reading behaviours continue to change and consequently determine their reading progress in English with time. It also reveals that different forms of extrinsic and intrinsic motivation co-exist and that the academic curriculum, EAP course instructors, and familial and societal values play a prominent role in initiating and reinforcing the learners' motivation. As motivated learners, the students apply various cognitive and metacognitive strategies and engage in increasing reading activities though inadequate guidelines and poor resources adversely interfere with their reading endeavours. It is also found that their diligence mediated by motivation contributes to improving their reading proficiency in English, and their reading accomplishments as well as their reading efforts reciprocate their reading motivation.