The Day of Souls is a holiday in which the citizens of The Nine Kingdoms gather to honor their deceased loved ones. Some even believe that on this day, the dead can return to Earth and walk amoung the living. The Day of Souls is usually a joyous -though somewhat creepy- occasion, though it's celebrated differently in each kingdom:
First- Continuing the tradition of dressing in costume to confuse any malevolent spirits who have returned, The Royal Family will be hosting a masked ball. You should bring some food or a small gift to honor those who have passed; these will be left as offerings in the town centre.