Several years after the wars between Humans and Orcs, an uneasy peace has settled over Azeroth. The defeated Orcs languish in internment camps, and the Human Alliance has begun to fracture without a common enemy. But a demonic army called the Burning Legion, having once corrupted the Orcs and sent them to invade Azeroth, is preparing a second assault on the world.
The story follows three paths that intertwine. Prince Arthas Menethil, a young paladin of Lordaeron, investigates a spreading plague that transforms its victims into undead servants, and his obsessive pursuit of the plague's source drives him toward a cursed blade and a terrible transformation. Orc warchief Thrall, warned by a mysterious prophet of the coming destruction, leads his people across the sea to the forgotten continent of Kalimdor in search of a new home. And Tyrande Whisperwind, leader of the ancient Night Elves, must defend her sacred lands from both the newcomers and the demonic invasion that follows. As the Burning Legion marches toward a source of power that could corrupt the entire world, these three factions must decide whether old hatreds or survival will define them.