This case study is based on teaching practice which is being developed at The Family Institute (Cardiff). We are interested in the underlying principles and processes in the application of systemic ideas to wide areas of different forms of practice including social work, health services and education services across statutory, voluntary and private sectors and in particular in the training of family and systemic psychotherapists. This particular case study looks at how the 'practicum' can become a moment of transformation in education and development - a moment when light floods the arena. During one particular study day with a group of professionals reflecting on their experience of how language defines systems and how feedback influences change in relationships and depends on context, we were struck by the energy the conversation had generated and we became particularly interested in trying to find a vehicle where some of what was being described about practice 'out there' might be experienced 'live' in the here and now for students. This case study describes a role-play exercise as such as vehicle.