Level 20, For Mithaniel Marr deity quest, escort them out of the cell back to the door of Crushbone keep, note that zoning out and then back into crushbone does not work, but escape might. If mobs are gray to you, then nothing will aggro them either. If mobs are not gray, have a real healer bc npc healer prob will not heal them as they are not pets to you and they will vigorously attack any mob in combat.