Someone nukes a city.
All the while, people have been falling comatose and rambling about mathematical formulas.
A lead is found after the PCs raid Fort Doom to free some slaves: the originator of the zombie plague and the bone machines is also causing the comas.
The PCs travel to the Broken Lands but are shot down and have to negotiate the Bartertown-like city of Corunglain at the edge of the wasteland.
The PCs finally find the BBEG, who turns out to be an Uncertainity Lich. He has been trying to do two things, pull an Adrian Veidt on the empires to forestall war, and buy back his soul from Acererak.
The PCs do the Adrian Veidt bit themselves 35 minutes before the BBEG has the chance to (much to my surprise), figure out how to defeat an Uncertainty Lich (also much to my surprise), free the people stuck in the mathy dream world and end the spread of the plague. Bad news: Acererak's plan actuall got a boost from this.
The PCs make it home to find out that their village has been annexed by the Black Eagle Barony and after defeating a neonate cosmic horror (?), they have to deal with a regional warlord and find that numbers do matter.
All the while with a lot of other stuff going on including possibly a mad time traveler, half the plot from Terry Pratchett's Going Postal, a cold war type situation still developing, the BBEG's apprentice still on the loose (her team is played by another PC group) and oh, nukes. And in the current timeline Acererak eats the universe and answers Isaac Asimov's Last Question.
Throughout all this 40% of the PCs died, one was chopped up to bits twice and survived (apparently you can be a Warblade without any limbs!), and more madness.