Thinking of nothing but revenge, Niccolo and Cadmus pursued Azazel and Beleth onto Earth only to have the portal shift and close behind them. The Horsemen found themselves standing on the plains of Napoli, their enemies nowhere to be found.

Once some allies from Hell come to the surface, Niccolo and Cadmus quickly discover something more important than mere revenge. As long as those two demons escape justice, there would be no way to know the designs of their tyrannical god or the dangers they will face in the coming Apocalypse.

So, even as Niccolo is plagued with memories of Lucifer's past and Cadmus is drowning in visions of the future, the Horsemen realize they have no other choice.

They will avenge Hell or die trying.