The War of the Spider

Beneath Northrend, the nerubians of Azjol-Nerub resisted the growing Scourge. Their living bodies resisted the plague, and their underground kingdom gave them tunnels and strongholds from which to fight. This was a people defending its home, not an undead army waiting to be discovered.

That resistance could not protect their dead. The Lich King raised fallen defenders and turned them against their own people. Anub’arak, once their king, was killed and compelled to serve the power he had opposed. Each defeat therefore cost the living more than territory: it gave the enemy more soldiers.

The kingdom fell, but its people were not entirely extinguished. Living survivors continued to resist in its ruins. The surviving nerubians faced undead enemies who wore the shapes of their former kin.

The Voice from Northrend

Kel’Thuzad followed the distant summons of Ner’zhul into Northrend, seeking powers his fellow mages had rejected. What he found was more terrible than a new school of magic. The undead kingdom demonstrated how death itself could become captivity.

His desire for knowledge did not spare him fear when he saw the plague at work. By the time he understood the cost of serving the Lich King, escape was beyond him. Kel’Thuzad pledged himself to his new master and returned south to prepare the way for the Scourge.

The Cult of the Damned gave the invasion willing servants among the living. Recruitment and concealed preparations preceded the open catastrophe in Lordaeron. When Arthas began investigating the plague, he was confronting the result of a campaign already underway.

A Dragon Bound to the Scourge

As Arthas hurried to reach his endangered master, Anub’arak suggested raiding the hoard of Sapphiron. The dragon’s artifacts could aid their passage through the north. They entered his lair as enemies, killed its defenders and took what they had come for.

Arthas did not leave the dragon dead. Though his power was weakening, he raised Sapphiron as a frost wyrm. The new servant helped clear the road toward the underground passage, but remained outside when the army entered the confined tunnels.

That encounter left a guardian the Scourge would use again. Sapphiron’s later presence in Naxxramas began with this act of conquest during the march to the Frozen Throne.

The Ascent to the Frozen Throne

The weakening Ner’zhul called Arthas back to Northrend. Illidan and his allies were moving against the Frozen Throne, and the death knight could no longer assume that the power sustaining him would endure. Reaching Icecrown became a race to preserve his master and himself.

Anub’arak offered a route through the fallen nerubian kingdom. The former king guided Arthas through tunnels haunted by the consequences of the Scourge’s conquest. For Arthas the passage was a shortcut; for Anub’arak it was the ruin of the realm he had once ruled.

At Icecrown, Arthas overcame Illidan and climbed to the prison above. He broke the ice and put on the Helm of Domination, joining himself to Ner’zhul as the Lich King. The prince who had taken a cursed blade to save his people now sat at the center of the power that had destroyed them.

Illidan survived the duel. Vashj and Kael’thas brought him back to Outland, where the failure left him preparing for Kil’jaeden’s wrath. Arthas gained a throne; his opponent returned to a kingdom that could not make him safe.