The process of psychotherapy invites the patient to explore their mind and the mind of the other but does so in the context of a therapeutic relationship in which the therapist is at least partly unknown. This article explores how patients, unbeknown to their therapist, explore clues that may disclose some knowledge about their therapists. One route towards exploring the unknown is through the therapist's social identities. The article presents an analysis of interviews conducted with 11 patients attending a free clinic in Johannesburg, South Africa. Their process of exploring the therapist and encountering the unknown, and wondering about whether their therapist can know them, is presented. The therapist's social identities offer a ‘glimpse’ into the therapist's mind. The article offers an alternative way of approaching inadvertent self-disclosure and invites therapists to be aware of their patients’ explorations of them that may remain unknown to therapists. Social identity offers a potential vehicle for alienation but also for connection.