Night-Caller (artifact)

The Night-Caller is an artifact that was found on an altar in a deserted room of the Scorched Shrine. It is a mysterious whistle, carved from what looks like bone, and resembles a small dragon curled up like a snail. Dwarven runes reading Azun-Gund are etched along the base.

Initially
While the heroes have initially been able to determine that the Night-Caller is indeed a magical item, projecting a faintly necromantic aura, they do not currently know how it works or what it does.

Update
Oghren Rustbeard was able to give the heroes some background information on the Night-Caller. He had heard that the ancient dark dwarves had made several such whistles for various groups in an age past. He was unaware that any of them were still in existence. The legends he knew of told that if the whistle was blown over a grave in the darkness of night, a corpse from below would rise and do the bidding of the whistler. He recalled stories of the horrible deeds committed by those in possession of a Night-Caller in times nearly forgotten.

The heroes have decided they will keep the ancient evil artifact safe until they can find a scholar at a holy temple that can help them properly dispose of it.