Prison Discourse is unique in that it embeds detailed linguistic analysis within a sociological description of an important and controversial area: the prison. Andrea Mayr provides extensive and powerful examples of spoken interaction between prison officers and inmates in a big city prison during a rehabilitation course based on improving cognitive functioning. She charts language use and shifting power relations within the prison and situates the linguistic study within the wider domain of power dynamics in institutions. She further clarifies the role that Systemic Functional Linguistics can have within a wider Critical Discourse Analysis perspective in supporting understanding of spoken interaction. The author's interdisciplinary approach ensures a highly relevant resource for linguists, educators and social scientists.