2007年にリリースされた本作は、PCおよびMacで提供されるMMORPGの拡張コンテンツです。プレイヤーは、再開された闇のポータルから侵攻する強大な悪魔の軍勢に立ち向かうため、荒廃した世界を探索します。ゲームプレイの中核は、レベル上限の引き上げによるキャラクター育成の深化、新エリアの探検、ダンジョン攻略、そして新たなプレイアブル種族であるブラッドエルフとドラウネイの導入にあります。
The content of this game is suitable for persons aged 12 years and over only. It contains: Non realistic looking violence towards human characters - Mild bad language
Fresh from his defeat in Outland, Kael'thas Sunstrider returned to the blood elf city of Silvermoon. Rather than lead his people to glory as he had promised, the disgraced prince betrayed them. Kael'thas plotted to use the legendary Sunwell, source of the blood elves' magical power, to summon the demon lord Kil'jaeden into Azeroth. Aided by a joint task force of blood elves and draenei, the Shattered Sun Offensive, Horde and Alliance heroes narrowly stopped both Kael'thas and Kil'jaeden, purifying the Sunwell with the help of the draenei prophet Velen.
Following years of battles alongside the old Horde, the troll warlord Zul'jin retired to the city of Zul'Aman, capital of the Amani trolls, where he called upon mysterious dark powers to rebuild his army. While the eyes of Azeroth focused on the fight against the Burning Legion and the expedition to Outland, treasure-seekers invaded Zul'Aman, rekindling Zul'jin's hatred of the outside world - particularly the high elves of Quel'Thalas. Upon hearing that these newly christened "blood elves" had become part of the Horde in his absence, the infuriated Zul'jin declared war on both Horde and Alliance.
In his quest to reign over all of Outland, Illidan the Betrayer had established a mighty stronghold for his forces within the Black Temple, a former draenei citadel. Yet his influence began to wane after the defeat of his most trusted lieutenants, including the traitorous former leader of the blood elves, Kael'thas Sunstrider. The resulting window of opportunity permitted Akama, an elder sage of devolved draenei known as the Broken, to rebel against the self-styled "Lord of Outland." Along with Illidan's former jailor, the stoic night elf Maiev Shadowsong, Akama helped a group of heroes infiltrate Illidan's seat of power and put an end to the Betrayer's reign once and for all.