April 2019. In an indigenous community in the Nepalese Himalayas, a ritual is performed for Sansari, 'the One of the World', to ward off coronavirus. Why respond to an epidemic with a ritual ? On what basis do we associate a virus with a spiritual entity ? How do we articulate anchoring in tradition and innovation ? What does all this tell us about the relationship of this population to the world ? In addition to a film on this ritual, this article proposes avenues of analysis and reflection on procedures of interpretation, of integration of the new and the foreign into a local system of knowledge and defense.