Uncover the mystery of 'Grey Mask' in Dora Amy Elles' thrilling novel. Charles Moray's return home reveals a clandestine meeting led by a man wearing a mysterious gray mask. As he overhears their plans to harm a girl if certain documents are discovered, Charles is shocked to recognize his former fiancée among the conspirators. When he stumbles upon the case of Margot Standing and her missing marriage certificate, Charles seeks the assistance of Miss Silver, a brilliant detective known for her knack in recovering lost treasures.