- "Seeking to reclaim their realm of old, Clan Pestilens attempted to re-conquer the temple-city of Quetza in the Imperial Year of 2489 IC. The Plague Monks emerged with such numbers and deployed so many Plague Furnaces that swathes of the jungle were covered in pestilent mist. The unnatural cloud could be seen for miles, rising like a thunderhead above the canopy. Only an untimely meteor strike prevented what was sure to be victory for the pestilent rat-host"
- —Accounts of the Battle of the Mist, circa 2489 IC.[1a]
The Plague Furnace is a disease-ridden altar dedicated to the Great Horned Rat and an unholy pulpit for a Plague Priest to preach the words of their faith. These mighty war machines are covered in runes and foul sigils dedicated to the vile Skaven deity. It is the noisome shrine of Clan Pestilens and ruination and corruption travels in its wake. The Plague Furnace is pushed into battle by a congregation of chanting Plague Monks, the creaking of its iron-shod wheels audible above the drone of devotional maledictions. The decaying chassis of the Plague Furnace is riddled with woodworm, but it is the vast and ornate swinging brazier that commands attention.[1a]
A glowing hot censer of wrecking ball proportions swings back and forth, issuing overwhelming heat and a roiling cloud that even simple beasts instinctively recognize as poisonous and unnatural. The rhythmic swings of the infernal furnace produce an ominous sound as the pendulous censer drags through the air, leaving a trail of deadly fumes and lethal contagions. It stings the eyes and assails the senses to gaze at the shimmering heat of the swaying globe. As the greenish vapours drift over the Plague Monks, it wets their tattered robes. This befouled fog begins to make the pox-ridden brethren twitch, their eyes bulging out in an unholy fervour for battle and blood-letting.[1a]
As the Plague Furnace is brought against the enemy, the Plague Monks strain more feverishly at the ropes, increasing the momentum of the blazing orb. As the frothing brotherhood crash the Plague Furnace into the enemy battleline, the rusty chains holding the great warpstone incinerator are let slip so the vast censer plummets into the middle of the enemy unit. The unholy payload continues to spew the deadly green-tinged warpstone fumes while it is hoisted back into place.[1a]