Till We Have Faces explores Queen Orual's lifelong battle to reconcile her religious heritage with her Greek tutor's agnosticism, brought into conflict when her beautiful sister, Psyche, believes she has become the sacrificial bride of the Wind-Spirit and loses him, when Orual demands proof. In old age, Orual writes and then appends corrections to her telling of the story, sure some day that wise Greek readers will judge between her and the gods.

Aged Queen Orual writes to eventual Greek readers asking they judge between her and the gods over how she has been mistreated. Orual begins her story the day her mother dies, and a slave shears her plain locks and younger sister, Redival's, golden curls. A Greek slave, the Fox, becomes their tutor while waiting for a half brother, who turns out to be another girl, the supremely beautiful and quick-witted Istra/Psyche.

An epidemic strikes, and a popular belief arises that Psyche can cure fever by touch. The King orders Psyche out among the people, who begin offering Psyche worship due to the jealous goddess, Ungit. The Priest rallies them to demand action to end the kingdom's many woes by having Psyche as the "Accursed," undergo the Great Offering on Grey Mountain. Orual argues against this craven act and offers to substitute for Psyche, but the King shows her in a mirror she is too ugly to be a god's bride.

In a final meeting, Orual fails to comfort her half-sister, because Psyche's belief the god of the mountain has been wooing her for years offends her intellect. Orual intends to accompany Psyche to the Offering and either free her or to kill her to keep her from the Shadowbrute's clutches, but collapses and raves in bed for several days. Recovering, Orual decides to give Psyche a proper burial, and Bardia, who trains her in swordsmanship, accompanies her on her quest.

Orual and Bardia find Psyche not dead at the Tree, but in a beautiful valley. As Psyche tells of her release by the Wind-Spirit, Orual grows impatient and demands to see proof. Their conflict over perception ends a draw, and they part with Psyche hoping for another chance. Too worked up about the "riddle" of Psyche's marriage to sleep, Orual receives a fleeting vision that increases her vacillation between allowing Psyche to be happy, however she wishes, and rescuing her from a horrible fate she is too blind to see as horrible.

After a brief return home, Orual undertakes a second mission, which quickly turns to sharp conflict. Psyche insists she is subject now to her husband rather than Orual who, seeing words accomplish nothing, stabs herself in the forearm and threatens to kill them both, unless Psyche puts her "husband" to the test. Certain her world will be destroyed, Psyche agrees to the fateful test, and is right. Orual watches the magical valley leveled by no Brute of a god but by a beautiful being. Orual resigns to her fate and her agnosticism vanishes, but she still rankles the powerful gods will not act out of kindness.

Back home, Orual strengthens her mind and body and vows never to show her face publicly again. Confrontation with the god removes fear of her father, and she begins standing up for herself. She acts decisively when thrust into authority, while the King lies dying. Civil war in Phars brings rebellious Prince Trunia to seek refuge, and Orual proposes to be his champion against pursuing brother Argan. Quickly victorious in battle on the day after her father dies, Orual enters upon a 40-year reign that restores prosperity, security, and institutes social reforms. Grown bored, Orual decides to see the world. During the trip, she hears Psyche's story, stripped it of its riddle, turned into part of the cult of a young goddess, Istra. This is intolerable, and Orual sets to writing the truth, but ends doubting the gods have any answers.

Knowing she is dying, Orual hurries to correct errors in her text, and works so hard she sees a series of visions, the most frightening of which convinces her she is the goddess Ungit. A climactic vision brings Orual to a judicial hearing of her case against the gods. Orual views a three-walled animated painting that shows how she and Psyche have cooperated, Psyche doing, and Orual bearing the grief. The gods are not silent, once their human interlocutor has a face. Orual surrenders to divine transcendence and dies writing a repudiation of her previous views.