The cursed keyring is a ring of keys discovered in a storage room in the company of a skeleton, and known at once for the cursed aura it gives off.
Jean-Zera worked the keys with a Mage Hand, unlocking one cell without ever laying a hand upon them. Yet when he essayed another door with the cursed keyring, it burst outward in Greek fire, searing both Jean-Zera and Miray cruelly and laying bare a screaming fire elemental beyond; whereupon Jean-Zera shut the door once more and made it fast.