The Abyss of Despair is a bottomless pit located in the centre of circular room behind a wooden and bronze door in the Unseelie mound. It has a railing made of silver wire and bones, which is enchanted that nobody can jump or accidentally fall in the pit. The only way how somebody can end up in the Abyss is to be thrown down.
Meredith notes the room with the Abyss has moved up in the mound to the main corridor. When she enters, she is ambushed by Siobhan and Rozenwyn. They along with Pasco plan to kill Meredith and throw her body along with Kitto and wounded Rhys into the Abyss.