Shadow Vault

The Shadow Vault is a neutral quest hub for the Knights of the Ebon Blade, located near Aldur'thar: The Desolation Gate in northern Icecrown. The Shadow Vault was originally controlled by the Scourge, and players are given a quest chain — started by either Thassarian onboard the Skybreaker or Koltira Deathweaver onboard the Orgrim's Hammer, the flying battleships that patrol the skies of Icecrown — starting with the quest, It's All Fun and Games, to work with the Ebon Blade in taking it as a base. Once the chain is complete upon their return to the death knight questgiver on either one of the battleships, the Ebon Blade NPCs will appear in and around the Vault through the new phasing system, in which it is constantly attacked by the Scourge.

Once in Ebon Blade hands, the Shadow Vault will have all of the amenities of an inn: An innkeeper, vendors for general goods, trade supplies and food. There are also runeforges for death knights (thus allowing them change their runes while in Northrend, and not have to Death Gate back to Acherus), a flight path, and the quartermaster for the Knights of the Ebon Blade.

The Shadow Vault's quests focus on taking out Jotunheim, a Vrykul town in which the vrykul engage in combat to be ascended to Ymirjar aswell as the nearby scourge saronite mine, the Weeping Quarry.

Cataclysm
At some point after the Lich King's fall, Kingslayer Orkus brought a Frostwyrm (Kasha) to the Shadow Vault where the Knights of the Ebon Blade nursed her back to health. The Shadow Vault is not seen in the post-Wrath of the Lich King era and is only mentioned.