The narrative combines legend and historical research to trace the island abbey's origins in a bishop's vision of the archangel Michael, subsequent miracles, and the growth of medieval pilgrimage. It examines the site's dramatic tidal geography, successive construction phases and reconstructions after fires and lightning, and architectural features from early columns to later vaults. The account also explores monastic life under notable abbots, the preservation of relics, local prophecies, hospitality toward travelers, and the abbey's symbolic role in regional conflicts and devotional practice.