Throughout Season 5, much has been made of the greyscale disease that plagues little Shireen Baratheon, with one of the highlights from Episode 4 being Stannis' rare flicker of emotion captured in a beautiful speech to his daughter. Shireen had previously asked Gilly all about her sisters who died of the condition, while there have been subtle but definite references from Jorah, Tyrion and the Priestess in Volantis to the Stone Men who suffer from the disease. Whenever a group or theme is mentioned in the show, you can't help but wonder why. Will somebody run into trouble with the Stone Men? Or are the references merely adding to the scene-setting in Essos?