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.
In appearance they are much different from regular Ghosts, having a purple/orange glow to them resembling that of somebody coming in or out of Invisibility, or the Invisibility Spell effect itself. They are enshrouded in a mist like other ghosts, but unlike that of the ghosts, it is in a matching color.
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.
- "Hmm? Does someone live among the dead?"
- "Agh! Pathetic mortal!"
- "The endless sleep comes for us all..."
- "Soon you will know the cold of death..."
- "We meet again, mortal!"
- "Eternal slumber awaits..."
- "You dare hide from me?"
- "Time to end your foolish charade!"
- "I will return..."
- "Mortal fool! No one hides from the dead!"
- "Ugh! Only a fool tries to kill the dead!"
- "I sense a presence.."
- They share their dialogue with a lot of other ghosts, such as the Companion Ghost.
- When Gallus Desidenius is first met, he is labeled as a Nightingale Sentinel.
- In the quest Darkness Returns, Gallus Desidenius is labeled as "Nightingale Sentinel" in the log.
- Casting spells that change the color of skin (such as frost spells leaving a cold effect or fire lighting up a body), the ghostly effect is removed and the actual colors of the Nightingale armor become visible.
- Stealing from or pickpocketing them might cause them to send Hired Thugs after the Dragonborn.