[1] In the prelude, taking place 3,000 years before Conan's time, a raiding army from the empire of Acheron descend on the city of Nithia, located near an oasis deep within the desert, inhabited by worshippers of the peaceful and benevolent god, Ibis.
The warriors systematically massacre the entire population, their goal being to gain possession of the Grim Grey God - an extremely powerful and evil artifact with mystical properties, which the priests have guarded for many centuries (not to use it, but to prevent it from being used).
However, rivals also seek to plunder all of Nithia, including Jade, empress of the thieves' guild, Toj the assassin, and two necromancers (one of whom is Conan's recurring foe, Thoth-Amon) convinced that the statue will give them the power to restore their reign of darkness over the world, as in the days of ancient Acheron.
In fact, this sender bore the opposite of love, the "gift" was a supernatural booby trap intended to kill the priest - but it was opened while on the way in Nemedia, caused the death of an innocent bystander, and was eventually disposed of by Conan's sword.
Howard did little more with the god Ibis and his priests in the rest of the canonical Conan stories, but the above information sufficed to provide the foundation on which the elaborate structure of the present book was erected.