Most accounts of bullying and intervention programs against violence in school deal with aggregate prevalence estimates and outcome measures. Case studies are rare. Bullying occurs regularly within classrooms. Psychological aggression through teasing and harassment is more difficult to detect. Bullying and bullies are relatively persistent, victimhood less so. The aim of this study is to increase understanding of the mechanisms by which bullying persists and to identify some of the factors which may facilitate successful single-case interventions. A single-case, holistic design based on opportunistic (that is, non-professional) involvement is used. One of the authors was a participant observer throughout the period of the case and acted as an action-researcher in implementing the intervention strategy, including contacting and informing the 'facilitator.' The case arose opportunistically within a rural, close-knit community. The bullying occurred in a one-teacher school with one classroom and 28 children aged 5-13. How the nature and extent of the bullying was discovered is described. A facilitator agreed to act, did act by enlisting three of the bully's peers to “police” the bully, and followed up the outcome until it was clear that the bullying had ceased. The successful outcome was put down to the facilitator's perceived seriousness, the collective intervention by peers, the immediacy of the reaction, the legitimacy of the physical force used (restraint of a schoolyard bully by peers), continued peer threat of it and the obvious intentionality of the intervention. The most important outcome for the victim was an expression of justice having being done.