The large round room is covered with jagged carved mirror surfaces that distort the shape of anyone inside. Every three rounds a pulse of bright light fills the chamber; occupants must Save vs spell or be blinded for 2d4 turns. In the moments of darkness between the pulses the ghosts of five, long dead, adventurers try to get the attention of any living intruders. They are desperate to get the necro engine disabled as they are unable to leave the mirror complex while the pulses persist. The 5 are all lawful and will continue to explore the dungeon as ghosts if freed.