From Ardrana

The quest spell enables the caster to require the affected creature to perform a service and return to the priest with proof that the deed was accomplished. The quest can, for example, require that the creature locate and return some important or valuable object, rescue a notable person, release some creature, capture a stronghold, slay a person, deliver some item, and so forth. If such a quest is just and deserved, a creature of the caster's religion cannot avoid it. A quest cannot be dispelled, but it can be removed by a priest of the same religion or more powerful than the caster. Likewise, an unjust or undeserved quest might automatically fail.

Note: This spell originally appeared in this form in the 2nd Edition Player's Handbook for Advanced Dungeons & Dragons from TSR. Its use here is for the purposes of providing context for the campaign only.