Harpers quest?

[Illumina Drathiran'ar]

Yep, that's the quest.
They wanted to do this to you:
Imprisonment (Abjuration)
Level: 9
Range: Touch
Duration: Permanent
Casting Time: 9
Area of Effect: 1 creature
Saving Throw: None
When the imprisonment spell is cast and the victim is touched, the recipient is entombed in a state of suspended animation in a small sphere far beneath the surface of the earth. The victim remains there unless a reverse of the spell, freedom, is cast. Otherwise, the victim will remain there as long as the earth exists, rather a horrible fate, actually. If a freedom spell is cast in the area where the creature was imprisoned then he will reappear exactly where he was last standing. Dispel magic will not free creatures trapped in this manner. There is no saving throw.

Fortunately for you, they failed.
You'd think one of the mages there would have that spell memorized, or have a scroll of imprisonment, or SOME way to cast that, no? Ah, well.