In this paper the author describes two separate experiences of working with Isabel Menzies Lyth, first between 1987-1988 and then from 2002-2005. She recollects Isabel's seminal role as staff group facilitator on a long-term rehabilitation ward at Littlemore Hospital, the McKnight Unit, where the author worked as a nursing assistant. She describes how Isabel's insights and interpretations in that group introduced the staff to a new way of thinking, and shed light on complex ethical and clinical dilemmas. She discusses the powerful, sometimes surprising, impact of Isabel's psychoanalytic understanding of psychosis, and of the anxieties that the staff team faced in this work. She then describes the experience of fortnightly supervision with Isabel, some 15 years later, when the author had qualified as a clinical psychologist and was working in a forensic unit with mentally ill offender patients. The paper is a personal recollection of Isabel's enduring insights and a description of her keen intellect, sensitivity and compassion in practice.