Well of Shiuan is a 1978 science fiction novel written by C. J. Cherryh. It is the second of four books composing the Morgaine Stories, chronicling the deeds of Morgaine, a woman obsessed with a mission of the utmost importance, and her warrior companion, Nhi Vanye i Chya.
Mija Jherun, a fey seventeen-year-old peasant woman, lives in a world inexorably being overwhelmed by the sea. One day, after looting a barrow, the tomb of a young warrior-king, she is chased by an armored man on horseback back to her village. He breaks into the poor home she shares with her family, helps himself to some food, and asks if anyone has seen a pale woman on a grey horse. After repulsing an attack by the men of the village, he departs for Shiuan, a richer land ruled by the khal, another race that is enough like humans to successfully interbreed.
Jherun, yearning for a less bleak future than marrying the thuggish Fwar, runs after him. Instead of finding him, she stumbles upon his mortal enemies: his cousin, Nhi Vanye, and Vanye's lord, Morgaine, the pale woman.
They inform her that Chya Roh's body had been taken over by an evil creature who had extended his life countless times by this means. He had betrayed Morgaine and sent ten thousand men to their doom a century before. Fleeing her, he had passed through a Gate from Vanye's world to this one, closing the passageway forever, but not quickly enough to prevent Morgaine and Vanye from following.
Jherun knows of two Gates, which she calls Wells. The newcomers had emerged from one; the other is in Shiuan. Morgaine's mission is to travel from world to world, closing their Gates permanently, as they can (and have in the past) destroyed whole civilizations when their immense power is misused. She is the last survivor of a band of one hundred sent for that purpose. Vanye is a chance-met warrior, bound to obey her initially by his stubborn sense of honor and later for other reasons.