Pretty much that. You know the object, somebody stole it. You don't have a clue of who or where does he/she have. Perhaps in this plane or in other.
Is there any way of directly locate it other than a wish?
The range isn't huge, but you could use repeated Augery spells to head int he right direction until you were close-ish. Commune or Divination would be good for that too.
Divination plus locate object sounds fairly good. Thanks!