Kel'Thuzad's Scourge was a group of Undead under the personal command of the Archlich Kel'Thuzad. Many months after the Burning Legion's defeat at Mount Hyjal, King Arthas Menethil had returned to Lordaeron to purge the remnants of the Humans who lived there. Kel'Thuzad led his own force of Necromancers and Ghouls in the northeast to prevent the humans from escaping. He later led his force to assist in destroying the villages and slew the Paladin, Magroth the Defender.