A sunflare, a meteorite strike, a tachyon storm - all natural disasters - were wiping out the best brains of mankind at a rate of a thousand times greater than normal.
The Director of ChaosCenter laid it out bluntly: "All our evidence suggests that a device that can alter probability exists. For want of a better name we call it the Chaos Weapon.
Somebody, somewhere, wants us cut back - and hard. Unless we find that Chaos Weapon and destroy it, it's going to destroy us!".