This inquiry offers a linguistic–pragmatic study of instances of bystander intervention, a social action that takes place when one or more bystanders intervene when a wrongdoer abuses a victim or behaves outside socially acceptable norms. It tentatively introduces the notion of intervention discourse to distinguish it from those used to achieve other communicative purposes and to reveal some recurrent patterns of language use in bystander intervention. This inquiry shows that the skillful exercise of deontic authority embodied in intervention discourse might have a tangible impact on the intervention result.