The Phoenix Ascent (The Fifth Column)

Can one alchemist and a rogue assassin turn the tides of war?
Hordes of the Mongol Empire sweep across Northern Asia, crushing everything in their path. As plague ravages the continent and the heavens burn with meteors, the empire’s greatest general will stop at nothing to possess the first Phoenix virus.
When Kaifeng, the Chinese capital falls, the only thing standing in the path of total domination is one lone alchemist and a rogue assassin.