Head to ( 1456, 415, -536 ) /waypoint 1456, 415, -536 and there should be an elemental with the title "The Wounded" under its name. Its is a ^^^80 heroic mob. This mob can spawn anywhere in the lost valley. Use Query Element then Dominate Element and it will become aggro. Kill it and retrieve your item off the body.
Return to The Apprentice
This quest is part of the Conjuror Epic Weapon Timeline, and can only be started/completed by a member of that class of at least Level 80.