Strange things happen in the mountains of Azerbaijan, even in the most normal of times. And these times, men whispered, were anything but normal.
First, the Army of the Dead. Nobody seemed to know precisely what had happened that dark and stormy night, when lightning struck the castle tower and insane laughter, louder than any human voice, could be heard across the valleys; what was clear, though, were the results, as strangely silent and shuffling soldiers began to fill out the armies of the Abbasid Caliph. It was al-Baradei's triumph, and the Mad Arab led the Dead against disloyal vassal or Mongol rider alike, and subdued all to the Caliph's allegiance.
And then disaster. Fatimids and Russians got wind of the breakthrough - for sadly, the smell of the grave carried far on the winds out of Persia, and terrified survivors spread word of soldiers under the Caliph's banner who neither tired with long marching nor flinched at the bite of iron - and soon Baghdad was beset with demands that it disband its "unholy" zombie army or face the wrath of the world united. However much al-Baradei argued, those whom he called the backwards, vision-less opponents of Science also commanded armies to outnumber even the Army of the Dead, and the Caliph was forced to give in. The risen were put down again, and the strange hissing machines of lead, copper, acid and rarer things from which they had sprung were smashed under the watchful eyes of Fatimid inspectors.
Nobody but his closest servants saw the Mad Arab for months after that, and they whispered of his terrible, violent rages.
Then, the Two Emperors' War struck the East, and the Fatimid overseers were expelled. Shortly into the war a sudden influx of building materials of all types was noticed in the valley in which the Arab made his home, but little more could be told; the peasants were forced to relocate and the entire area placed under the guard of the Caliph's picked troops. None were allowed in without the personal approval of either al-Baradei or the Abbasid himself, but whispered rumors nevertheless spoke of strange towers and massive disks under construction in the hidden valley, and the keepers of the Baghdad library scratched their heads as constant sendings for Greek works of geometry and mathematics replaced the requests for tomes of religion and the necromantic secrets of the pharaohs.
And then soldiers began to die on the borders of Persia, men who were healthy last week coming down sick, heaving up the contents of their stomachs and, eventually, blood, while their hair fell out in clumps. At the height of the war Fatimid armies in the tens of thousands died within days in Syria, and dessicated corpses were stacked outside Damascus, higher than the city walls. None of the Fatimid's wisest could seem to agree whether it was some disease - for it did not seem to spread beyond those first infected - or a poison, for the dead often shared no common well or source of food.
Stranger still, the next news was of another army dying - not Fatimid, but Greek. Outside the walls of Constantinople, the strange affliction struck yet again and twenty thousand of the Emperor's best, along with their commander were lost to the allied cause. Many now thought to ascribe the deaths to God's curse on those who broke His peace, rather than malice out of Persia - for the affliction struck friends as well as enemies, and none remembered that the Greek commander's father had once attempted to have a certain man blinded on charges of witchcraft and sorcery.
At long last, after oceans of spilled blood, peace was agreed upon, the Fatimids and Russians taking large swathes of land from Persians and Greeks whose confidence had wavered despite their enemies' immense losses. And the strange plague ended as soon as it had begun. But in Azerbaijan, al-Baradei's Valley remained closed to all, and though none of those who slipped past the Caliph's guards ever returned, whispered stories of bizarre contraptions and unbelivable machines continued to make their way out of the mountains.