The "Grey Year".

A colony spacecraft from the distant world of Celthar arrives in orbit. The Celtharians establish a self-building output near the border of Nexdor and Malboria that begins to consume and rebuild all matter in its vicinity, turning it into atmosphere processing equipment and other colony structures.

Molinar along with skilled sorcerers from neighboring kingdoms unite to stop the threat. Wielding magic — a phenomenon unfamiliar to the aliens — they shatter the colony, kill the crew, and cripple the orbiting colony ship. Possession of Celtharian artifacts is made a capital offense.

Historians refer to 744 as the Grey Year, both for the invaders' grey skin and for the stormy, overcast skies caused by their equipment.