Zenia’s burrow is covered in cobwebs and ruined, save for the pile of written prayers buried by mortals. Matilda burns them until she realizes some of them are addressed to her, including a blood-stained one from Vincent that states, “Matilda, help me” (134).

Bade enters the burrow, and they hug. He tells her that she’s welcome to stay with him and Adria, though he has been cast out of court. Phelyra has only just returned after a decade of exile because Dacre wants to ally himself with her power. Bade also tells Matilda that Orphia wants to see her.

When Matilda visits Orphia’s burrow, Orphia is at her loom. There is a man that Orphia doesn’t want to die yet, but Rowena has unpicked Orphia’s weaving. Matilda can save the man from death if she delivers to him a message from Orphia, instructing him how to avoid death. Matilda agrees to take it, and she looks at the name on the parchment: Vincent of Beckett, Lord of Wyndrift.

Matilda’s magic shows her where Vincent sits in his family fortress. She wonders what happened to his father and his older brothers to make him Lord of Wyndrift. She hurries out of Orphia’s burrow and toward the mortal world to save Vincent’s life. Matilda sees that there’s one more hour of daylight left as Vincent’s family’s fortress appears on the horizon. She puts on her invisibility cloak and approaches the castle.

A large war camp is sprawled across the surrounding area, blocking the eastern gate. Matilda sees a raven and asks to borrow its sight, a power Skywards wield. The raven flies, and Matilda sees the massive bridge fortress, dividing the land surrounding the river into east and west.

Matilda senses Vincent in the castle’s tallest tower. As the raven flies closer to the window, she sees Vincent, now a man, sleeping, as an army gathers at the edge of his fortress. Matilda needs to warn him, and the fastest way is to travel by rivers. She calls upon the god of rivers, iron, and spring: Warin.

Warin arrives quickly, which surprises Matilda, as their last parting was bloody. She asks to borrow his power over rivers from sunset to sunrise. Warin’s never lent his powers to anyone, so he refuses, but he does offer Matilda a pair of slippers that will let her walk through rivers and breathe underwater. He stipulates that she return the slippers to him personally when he asks. Matilda agrees, with the caveat that he cannot detain her when she returns them. He negotiates for dinner when she returns the slippers, and Matilda agrees.

The slippers fit Matilda perfectly and let her walk through the river and breathe underwater. Her magic tugs her toward Vincent, and she thinks of what Orphia said to her about him: “He was mine to take before one dark solstice night, but I refrained, curious to see who he would become…He is doomed when the clouds break, and the moon shines through” (150). Matilda thinks the weaving of life and death is a game between Orphia and Rowena.

Matilda reaches the tower and climbs out of the river, her cloak still hiding her. The cloak rebels, turning colorful, and archers shoot at Matilda as she climbs the tower. Arrows pierce her back and her calf, but she makes it into Vincent’s window. At first, Vincent doesn’t recognize her, which hurts Matilda. When he looks at her closer, he says her name.

Vincent should’ve recognized Matilda immediately, but he hasn’t thought of her in years. He asks her why she’s there, but before she can answer, Edric enters. He offers to take Matilda to the keep, assuming that she’s an assassin. Matilda asks to speak with Vincent alone, and Vincent agrees. He sends Edric to fetch wine and bandages for Matilda’s wounds. Edric realizes Matilda is a goddess.

Matilda pulls the arrow out of her calf but needs Vincent’s help removing the one in her back. He straddles her while she lies face down on the floor. He hesitates to pull the arrow, as he doesn’t want to hurt her, so he channels the rage and sorrow he felt when she didn’t answer his letters and pulls the arrow free.

Matilda tries to hide her pain when the arrow comes out, but she winces. Vincent presses on the wound with his palm until it magically heals. Alyse arrives with bandages and wine. She offers Matilda fresh clothes and leaves to fetch them.

Alone again, Matilda asks Vincent about the war camp outside his castle. He is angry at her for showing up and asking about his war after abandoning him years ago. Vincent claims he would have imprisoned or killed any other god that came through his window. His irreverence scares Matilda, as she knows irreverent mortals have targets on their backs.

She and Vincent share the wine, and Vincent tells her about Grimald’s betrayal in the Dark Winter, 10 years ago: On the winter solstice, the people of Wyndrift assembled in the fortress hall to celebrate. Grimald stood to give a toast, and then a third of the Wyndrift knights betrayed Vincent’s family. They slaughtered his father and brothers. Vincent was stabbed and played dead until Edric found him and dragged him to where Alyse was hiding with his youngest brother, Nathaniel.

Vincent has since waited for Grimald’s return as he obtained land, men, and power nearby. Grimald is angry because he believes himself the rightful heir to Wyndrift; he’s the oldest son, and tradition dictates the eldest son be heir, but Vincent’s grandfather named his father, the second son, heir.

The fighting will begin at daybreak, but Grimald wants to parley with Vincent beforehand. Matilda gives Vincent the letter from Orphia, but he refuses to read it, as he doesn’t want to be beholden to any god. Matilda begs him to accept her help if he won’t accept Orphia’s. Vincent doesn’t trust the gods or Matilda. She asks Vincent why he’s talking to her, why he helped heal her, if they aren’t friends. She also reveals she’s both Underling and Skyward. Vincent apologizes for being cold to her and asks her how she can help him. Matilda says they must both attend the parley with Grimald as husband and wife.

Matilda waits for Vincent to laugh at her idea, but instead, worry lines his face. Matilda asks if he’s already married or engaged, but he’s not. Matilda says that the wedding can be a ruse, as she’s unwilling to vow herself to anyone in earnest. She refuses to leave his side, as she’s convinced he’ll die if she leaves him alone.

Alyse returns with clothes and asks if the wedding is real, and Vincent confesses that it’s a ruse that must remain secret between the three of them. When she leaves, Nathaniel arrives, much older than Matilda remembers him. He insists on having a wedding feast to allow the people of Wyndrift to meet Matilda. Alyse dresses Matilda in a wedding gown, but she insists on keeping her slippers and moonstone belt on. She and Vincent face each other and take each other’s hands.

Vincent tells Matilda that they must appear in love. He must touch her as if it’s second nature, so they agree to practice. Edric meets them and guides them toward the part of the bridge where they must meet Grimald. Vincent tells Edric to remain behind, close to Nathaniel, while he and Matilda journey through the three towers, Rye, Maiden, and Fury, that mark the different sections of the bridge.

The middle tower, the Maiden, feels enchanted to Matilda, and she thinks an Underling door is nearby. Matilda understands why Vincent always dreamt of drowning, since the towers and bridge are built atop the river, not on the banks of it. Vincent says Grimald often threw him and his brothers into the river and made them swim against the tide, demonstrating his cruelty.

Matilda and Vincent reach the Fury Tower and greet a knight named Lady Hyacinthe. Hyacinthe leads them to Fury Gate as Vincent gives his knights orders not to engage in conflict, no matter what happens. Matilda suggests that she pretend to be a mortal woman, leaving her moonstone belt behind. Vincent agrees, as long as she promises to protect Nathaniel if Grimald kills Vincent. They step onto Fury Bridge together.

It’s been 10 years since Vincent has seen Grimald, who is gray and older but still proud and cruel. He holds Grimald’s gaze as he approaches with Matilda. Grimald is with his advisor and squire in the parley tent. Grimald thanks Vincent for bringing him a gift, referring to Matilda, but Vincent says that Matilda is his wife, and the parley has interrupted their wedding feast. Grimald is shaken, as marriages are more powerful alliances than blood, and he doesn’t know who Matilda is. He asks why he wasn’t invited to the wedding, and Vincent calls him an unwelcome traitor.

Grimald asks Vincent to turn over Wyndrift to him, claiming that tradition makes it his. Vincent refuses. Grimald comments on Vincent’s new courage, reminding him of his escape from his brothers’ grisly fates and triggering his feelings of guilt. Grimald also alludes to Vincent being born outside of marriage, bringing up rumors of his mother’s infidelity.

Vincent strikes back, telling Grimald that no one in Wyndrift misses him and instead refer to him only as “the betrayer,” as he knows Grimald’s deepest desire to be loved and revered. Vincent refuses to peacefully yield to Grimald, and he notices Grimald’s hand signal a moment too late. An assassin fires an arrow at Vincent, but Matilda moves in front of him.

The arrow catches Matilda in the chest above her heart. It misses her fault line, so Matilda stands and removes her veil. Grimald demands that his troops halt where they were sneaking up under the cover of night. Matilda sees Orphia among the retreating troops. She nods to Matilda, showing that Matilda has succeeded in saving Vincent.

Grimald tries to appeal to Matilda, but she tells him to leave before she and her allies punish him. Grimald claims it is too muddy to retreat and asks for three days. Though Matilda worries it’s a trick, she agrees and pulls the arrow out of her chest, casting it at Grimald’s feet. Before he leaves, Grimald tells Vincent that he’s glad Vincent finally took his advice to capture and use Matilda, which makes Vincent stiffen and reminds Matilda of Grimald’s cruel intentions.

Alone on the bridge, Vincent tells Matilda to never risk her life for him again. They return to the fortress to attend their wedding feast, and Matilda dons her moonstone belt. Matilda sees that peaceful craftspeople are “the heart” of Wyndrift. She knows that Grimald won’t retreat in three days and feels responsible for protecting the people of Wyndrift.

Vincent gives a speech explaining the events of the parley and his new marriage to Matilda, pretending they made vows alone in his bedchamber. They toast, and Vincent tells Matilda they must kiss. They kiss chastely, but Matilda pulls Vincent closer, feeling warmth in her body.

Matilda and Vincent retire to his bedchamber. He offers her the bed, but she informs him that gods rarely sleep; she intends to sit by the fire and plan. She tells Vincent that Grimald will not retreat, so she will go to Bade and ask for his assistance. She advises Vincent to ask his allies for help and to evacuate all those who can’t fight to somewhere safer.

Vincent hasn’t considered evacuation, as the fortress is supposed to be safe, but Matilda warns him that Grimald could have allies attack from the west. Vincent knows that Hugh of Delavoy, his father’s old ally, has the lands to the west, but Hugh has sworn Vincent no oaths. Vincent has written to Hugh and asked for help, and he refuses to send Matilda to deliver an additional missive. He agrees to evacuate the vulnerable to Drake Hall, a historic Delavoy property.

Vincent asks Matilda about her past. She tells him snippets about who her parents are, how Bade became her ally, and how Phelyra murdered her mother. Vincent offers sympathy, but Matilda doesn’t want to be vulnerable, so she claims to be happy she was sent to Skyward to grow in strength.

Matilda tells Vincent to rest, and he gives her a wedding gift: a necklace with a small jar of bittertongue, or river blythe, a flower that grows only near the river. People who move to the river are given a vial to wear for a year to protect them from the flower’s poison. Matilda keeps a vial with her in her belt to collect burnt Skyward prayers, though she’s never received one. She looks out the window and sees Grimald’s men burning prayers. She slips into her cloak and leaves, going into the river.

Matilda, hidden by her invisibility cloak, uses the river to sneak to Grimald’s tent. She watches him burn prayers until Warin arrives. Grimald asks for Warin’s help in battle, as he wants the river, and Warin is the god of rivers. Grimald also reveals Matilda’s marriage to Vincent, which shocks Warin.

Warin agrees to help in exchange for being the true controller of the bridge, exacting a toll for each mortal crossing. Before he elaborates on what the toll is, the wind blows, sending the scent of Matilda’s magic into the tent. Warin says they must continue the conversation later, as he must hunt. Matilda runs.

Matilda runs as Warin chases her. She wants to reach the bridge, to cry sanctuary in hopes that the mortals of Wyndrift will let her in. Warin mocks her for thinking the mortals will help her. He grabs her violently, questioning why she used him to cross the river.

Matilda calls to the gatekeeper for help repeatedly, but no help comes. Warin humiliates Matilda, telling her that Vincent doesn’t care. Matilda hopes Vincent is sleeping and can’t see her being overpowered by Warin. Matilda hears someone shout from the tower as Warin drags her into the river.