The verger is a character in the story, Canon Alberic's Scrapbook. The verger, also called the sacristan, is employed as the caretaker of S. Bertrand's Church. When Dennistoun investigates the church, the verger is visibly afraid of something. He later sells Dennistoun Canon Alberic's scrapbook, who then realizes his fear as he sees a demon comes out of the book.
Canon Alberic's Scrapbook