Nightingale Sentinels are dead Nightingales, since all Nightingales are bound by oath to defend the Twilight Sepulcher after their death. During the Pilgrim's Path quest the Dragonborn encounters them in a confused state wherein they do not recognize the Dragonborn as a fellow Nightingale; this is due to the closing of Ebonmere when the Skeleton Key was removed by Mercer Frey. When they die they leave behind a blue pile labeled Ghostly Remains. In appearance, the pile of remains is like that of most Ghosts and Ice Wraiths.