"The Key is a kind of magical artifact with no fixed physical form that can be used to open a gate between worlds. Glory's home dimension is unusually difficult to access; she wants to use the Key to go home. The monks we saw were trying to keep it from her, and when she discovered them they cast a spell to hide the Key in the safest place they could think of: under the protection of that undead ex-Slayer with mysterious powers who's been making diplomatic overtures to so many demons lately."