This talk follows the remarkable afterlife of a lie: the accusation that the Jews of Brussels desecrated the Eucharistic Host in 1370. From its thin medieval traces, the story grew into a grand civic myth, told through paintings, processions, and stained glass, that came to define Brussels' religious and urban identity for centuries. Dr. Cassen explores how this legend was used to serve both church and state, and how even after the Holocaust, efforts at reconciliations stopped short of confronting its falsehood. In tracing the evolution of one fabricated story, we'll consider what happens when myth becomes history- and whether it is possible to undo that transformation.