The novel is set in Iraden, a small territory on the Shoulder Sea, governed by a pact between two gods. The Raven of Iraden inhabits a succession of raven bodies called Instruments and shares power with a ruler known as the Raven's Lease, who must voluntarily sacrifice his life when the current Instrument dies, providing the god with power. The God of the Silent Forest, inhabiting the vast forest south of Iraden's fortress town of Vastai, is party to this arrangement. The story is narrated in second person by a mysterious, ancient entity addressing a character named Eolo, unfolding across two timelines: a political crisis in Vastai and the narrator's own history stretching back millions of years.
Eolo, a soldier and aide to Mawat, the Lease's heir, rides with Mawat toward Vastai. Mawat has been summoned because the Instrument is near death. The narrator notes that Eolo binds his chest and conceals aspects of his body. When Mawat offers to ask the Raven to change Eolo's body, Eolo refuses, saying he already is who he is.
At the Raven Tower, Mawat finds not his father but his uncle Hibal on the Lease's bench, wearing the white garments of office. Lord Radihaw, the senior Direction (a member of the governing council that shares authority over Iraden with the Lease), and Zezume, the Mother of the Silent (head of a religious order that approves each new Lease), explain that the Instrument died unexpectedly and Mawat's father vanished. The Raven's reply is equivocal: "This is unacceptable. There will be a reckoning" (16). Since Hibal sat on the bench and survived, the god apparently accepted him. Mawat insists his father never fled and storms out.
Through a parallel storyline, the narrator reveals its identity. Its earliest memories are of the ocean floor among trilobites, long before humans existed. Over geological ages it became a massive stone on a hillside. When humans arrived, a priest taught the narrator language through offerings and carved tokens. The narrator befriended the Myriad, another ancient god who fell to earth as a meteorite and inhabited swarms of mosquitoes. In this world, a god's spoken words must be true, or its power forces them to become true; speaking beyond one's power can drain or kill a god.
In Vastai, Mawat locks himself in his room while Eolo investigates. Lord Dera, the Direction for Eolo's home district, reveals Hibal plans to move the Lease's household to Ard Vusktia, the city across the strait, which would strip the Directions of influence. Eolo meets Dupesu, one of the Xulahn travelers, foreigners seeking passage north. Dupesu carries a small brown snake Eolo suspects is a god and hints the Xulahns might support Mawat against Hibal. A flashback establishes Eolo's competence: During a border operation against the Tel, Eolo infiltrated an enemy camp with Mawat and later restrained Mawat from killing Airu, a disobedient councillor's son, by pointing out the tactical cost.
When Mawat emerges, he suspects Hibal orchestrated their father's disappearance and sits naked in the square before the fortress gate, a traditional act of public shaming. Hibal summons Eolo to the tower roof to question the Raven with divination tokens. There Eolo notices a second stairwell leading downward. The tokens produce unsettling fragments, including references to deception and the theft of another's power when asked about the Xulahns. That evening, Oskel and Okim, twins who serve Hibal, attack Eolo in an alley. Tikaz, Radihaw's daughter, tends Eolo's injuries and discovers his bindings. She asks if he is a woman; Eolo says he is not, and Tikaz accepts this. Tikaz reveals that only the Lease can descend the second stairwell and return alive, meaning only Hibal's word confirms the previous Lease was not found below.
A tower servant secretly tells Eolo he heard Mawat's father screaming for help below the tower. With the servant's help, Eolo descends. He finds Mawat's father still alive, bound in an alcove among stacked bones of previous Leases. Behind a massive door, he discovers a huge black-and-white stone turning ceaselessly in a circular depression, powered by water-driven wheels. The narrator speaks aloud to Eolo for the first time. Hiding, Eolo overhears Hibal reveal his plan: He keeps the previous Lease alive as proof the Raven survives, since the Lease can only die by sacrificing himself to the god. Hibal claims the Raven has been too weak to protect Iraden for nearly a century and that the turning stone sustains all divine obligations. He plans to let the Raven die and invite a replacement. On the floor, Eolo finds a leather cylinder wrapped in snakeskin, a godspoken object (one imbued with a god's spoken power) that renders its holder undetectable.
The narrator's ancient history continues. During a war between the Raven and the gods of Ard Vusktia, the Myriad persuaded the narrator to travel south to help the besieged city. Rather than lend its power directly, the narrator declared that while turning, it would grant the petition of whoever caused it to turn, making itself a godspoken thing on its own terms. When the Raven launched a final assault, sending thousands of wooden soldiers across the waves, he spoke the deaths of all gods who fought for Ard Vusktia. The narrator lost consciousness.
Eolo reports everything to Mawat, proving the cylinder's power by vanishing from Mawat's grip. Together, holding the cylinder, they enter the tower unseen and descend to confront Mawat's father. Consumed with disgust, Mawat declares his father failed his obligation and refuses to free him. An entity calling itself the god of Vastai tells Mawat through the tokens to stop the stone's mechanism. Despite Eolo's warning that this may not be the Raven, Mawat smashes the wheels with a hammer.
At dawn, Mawat drags Zezume from the headquarters of her religious order into the street. Zezume insists she confirmed Hibal to save Mawat's life. Guards seize Mawat; Okim stabs at him, but Radihaw steps between them and takes the blade. Eolo presses the cylinder into Mawat's hand, and Mawat vanishes. Eolo warns him that Dupesu can see through the cylinder's concealment.
The narrator reveals that after Ard Vusktia fell, it woke beneath the Raven Tower, trapped and turning. Because it had declared itself a godspoken thing, and the Raven's machinery was turning it, the narrator was compelled to grant the Raven's demands. For decades, the narrator has done the Raven's actual work: protecting Iraden from disease, fire, and invasion. The Raven's fatal error was speaking the deaths of all gods who fought for Ard Vusktia, but the narrator and the Myriad are both Ancient Ones, primordial gods from before human language who are nearly impossible to kill. The Raven's unfulfilled words drain his power unceasingly.
With the stone stopped, Iraden's protections fail. Fire, storms, and illness strike Vastai. Tikaz, vowing to avenge her father Radihaw, kills Oskel with a knife Eolo covertly passed to her. A messenger reports that the Iradeni border forces were destroyed in a Tel ambush; nothing stands between the Tel and Vastai except the forest. When the Raven is consulted through tokens, the answers confirm the Tel will arrive by the next day and that the God of the Silent has done nothing for years and may be dead.
Mawat reveals himself atop the tower, holding Hibal at knifepoint. Dupesu emerges from below the tower, having descended and returned alive, proving the Raven cannot enforce even this protection. He offers the snake god's help, but Mawat refuses. When Okim attacks Mawat, Okim drops dead, apparently killed by the Lease's divine protection. Mawat then slashes Hibal's throat as a sacrifice, declaring himself Lease. But the snake god speaks a death upon Mawat, and he collapses. Eolo kneels beside him, weeping.
The narrator speaks aloud through the stones, declaring itself the Strength and Patience of the Hill and the true god of Vastai, who has sustained Iraden all along. It warns the snake god it will not be the first god the narrator has killed. It tells Eolo to look northeast, where sails on the horizon carry the Myriad. The narrator instructs Eolo to help Zezume and Dera down the stairs, take Tikaz, and flee west under its protection. As for the rest of Iraden, they must take their chances with the Tel, with Stalker, or with the Myriad. The narrator's final words: "It's time for me to throw this tower down" (408).