From publisher blurb:
You've seen the horrors of the war between the divine and the infernal. You've heard the rumors of the Magi, adored masters of magic. At your side, faithful companions have fought. Now witness as the virulence spreads...
Virulence includes:
An expanded history of the world of Contagion
Detailed treatments of the eight Schools of Magic, shadowy organizations which hoard the arcane secrets of mysticism
In depth profiles of the eight angelic choirs and the eight demonic castes
Six new playable races
Eight new character classes including Advanced and Prestige classes
30 new Feats
The Advanced Arcane Spellcasting system
Expanded player and GM resource material for each race and class listed in the core rulebook
Much more!