The Storm of Heaven — Thomas Harlan

The great three-sided war continues, Rome against Persia against the tribes of the desert now commanded by Mohammed of Mekkah. The tide is turning against the Eastern Empire --the Emperor Heraclius lies bedridden in Constantinople and his brother Theodore has lost a great battle to the tribes. In the West, Rome lies devastated by the long-pent eruption of Vesuvius. And in the hidden valley of Damawand, the Persian sorcerer Dahak plots his revenge.

But there is hope for the West. Prince Maxian has learned that the Oath need not be broken; it can be changed by a skilled sorcerer. In Judea, young Dwyrin is coming into his full powers, honed by sorcerous combat with his friend Odenathus, who now leads the shattered remnants of the army of Palmyra. And among the Goths north of the Danuvius, a new legion is being forged, by a very old general.