Teachers have long participated in collaborative research. However, they have generally had direct stakes in the outcomes. Teachers in the Early Professional Learning (EPL) Project used their insider status to gather data not directly related to their own practice. Lessons for integrating a group of teacher-researchers into a major project are discussed. Some of these are practical, but also cover their unexpectedly experienced initial isolation within the project team, that has relevance for both forming and theorising communities of enquiry. An outline for a new concept of teacher-researcher begins to emerge that may influence the direction of educational research.