“Reflective practice” is a term imprecisely understood and used to describe a wide range of different activities or interventions. In this article I examine the Reflective Practice Group (RPG) as an intervention offered to multidisciplinary teams (MDTs) in mental health and social care settings. Drawing extensively upon the work of Wilfred Bion and on the “Northfield I” experiment which he led in 1942, I formulate the existential, conceptual, and functional challenges of the MDT in terms of the problematic interplay between the drive towards autonomy and the exigencies of interdependence. I take this interplay as the figure, with the ground being the baseline disarray of traumatised systems that both defines and contextualises the individual worker's predicament within the team. Analysing the nature of the MDT sheds new light on longstanding controversies about what ailment the RPG is there to address; what skill set is needed to facilitate it; and what methodology may be most appropriately used for its delivery.