Part 5/8:
Despite Tulkas’s formidable skills, the passage of time saw him grow weary. Melkor, seized by a hatred that festered over the years, waited until Tulkas fell into a deep rest to return to Middle-earth. Under the cloak of darkness, he constructed a fortress known as Utumno, initiating a reign of corruption that ultimately led to the decay of the natural world.
As Tulkas slept, forests began to wither, rivers soured, and the creature population turned hostile. By the time the Valar realized what was happening, chaos had already begun to grip the lands.