Purpose(#br)The purpose of this paper is threefold: first, to examine how buyer-supplier episodes are characterised by their dimensions of time and social space, and how these dimensions interact to impact the criticality of an episode; second, to explore how time and social space create patterns of episodes that lead to buyer-supplier relationship change and continuity; and third, to examine the social space by the different roles that the buyer assumes among their episodes, while focusing on the concept of critical time to denote the temporal context. (#br)Design/methodology/approach(#br)A case study of a small retailer and five suppliers is employed. The primary data are e-mail communications between the buying and selling firms, along with a two-week field study at the retailer’s... location. A total of 2,000 e-mails are coded to yield 75 episodes for the analysis. (#br)Findings(#br)The criticality of episodes differs depending on the role that the buyer assumes, and whether the episode occurs within a critical time period. The social space affects the type of criticality, while critical times enhance an episode’s criticality. This study outlines five different patterns of episodes occurring within critical times and across social spaces that characterise each of the buyer-supplier relationships. (#br)Research limitations/implications(#br)This paper focuses on e-mail communication, with little data on interactions occurring outside of this medium. (#br)Originality/value(#br)To the researcher’s knowledge, this paper is the first to link specific patterns of episode characteristics to the concept of buyer roles. It also examines episodes using e-mail communication, which is not a common source within the IMP research stream.