The next day, Rune and Draven travel in tense silence with his friends and an elven envoy to harvest zenith from a cavern within the Immortal Realms. The elven leader, Alvor, explains his soldiers killed a toxic drake, though the site remains dangerous. They cross a deadly chasm on narrow stone pillars to reach the cavern. While the others are distracted, Rune confronts Draven about their earlier fight; they apologize, and he calls her his salvation and damnation.

As the group collects zenith coated in toxic slime, a mysterious blue flame leads Rune to a hidden passage containing a dead elf. In the corpse’s hand, she finds a carved black zenith wand that she recognizes as the Darkstone, one of four legendary Arcadian Artifacts. When she takes it, a light reveals that the drake they believed dead is actually alive, lurking above them.

Rune screams a warning as the beast attacks, killing multiple soldiers. Draven creates illusions to distract it while Rune hides the wand in her tunic. The drake sprays acid, burning Rune before he heals her. They attempt to escape, but a lion-sized hatchling emerges behind Draven. Seeing him in mortal danger gives Rune the hope needed to finally summon the Star Arcana, forging a sword and shield of light. She blocks the mother drake’s acid and stabs it in the eye while Draven fights the hatchlings. Together, their combined fire kills the mother drake. As smaller drakes swarm, Draven throws an activated shard of zenith into a large pile, grabs Rune, and leaps from the cliff. Behind them, the cavern explodes.

Earlier, while the drake still distracts the others, Draven confesses that his heart will always belong to Rune, and she kisses him in response before they attempt their escape.

The group returns to Sedah with many casualties. Eldarion denies knowledge of the living drakes, though many suspect the attack was deliberate. After burning spying crystals in their Hearth, Rune shows Draven the Darkstone wand. Ecstatic, he tells her to hide it. Commander Soto escorts him to the palace, where his father confines him away from the Forge for the rest of the semester, fearing Eldarion and Altair have formed a secret alliance.

Days later, Malik delivers a letter from Draven containing a twinsoul pen that allows instant written communication. The letter reveals Draven’s father suspects a spy at the Forge and that the drake attack was orchestrated. Rune and Draven begin a regular correspondence mixing intelligence with playful banter and increasingly intimate exchanges.

Draven reports progress on their plans: he has narrowed the list of candidates for Rune’s brother and continues searching through palace records and contacts for more information. Through their letters, he deduces that his birth father possessed the Oathbreaker cup, another Arcadian Artifact. Following his instructions, Rune finds a book illustration confirming the cup is hidden in Kieran Ceres’s tomb. Draven later writes that he has retrieved it from his father’s grave, defiling the site to recover the artifact.

Weeks pass. Ember’s relationship with Kasper remains troubled, though they reconcile publicly. Rune continues her training at the Forge and spends her nights exchanging messages with Draven, deepening their connection. As the semester ends and her soul-day approaches, Rune realizes with shock that she loves Draven.

After completing her final exams, Rune expects to wait until the Winter Solstice to see Draven again. On the morning of her 21st soul-day, he surprises her by arriving with roses. Their reunion quickly turns into a celebration when both groups of friends join them.

That evening, Draven gives Rune three gifts. The first is information: a list of five elves who could be her brother, confirmation that her mother has been freed from Eldarion through blackmail and is now at the Sedah palace, and news that Rune will join a delegation to Eidolon during the Autumn Equinox to search for her brother. The second gift is the Oathbreaker cup, retrieved from his father’s tomb.

The third gift is a question. Draven presents matching crystal and diamond cuffs, tells her he loves her, and asks her to rule beside him as true partners. Rune accepts, admitting she loves him too. As they embrace, Draven is suddenly stabbed from behind.

Kasper holds the bloody blade to Draven’s throat, having stolen his tarot deck. He demands Rune surrender her cards or he will kill Draven. When she complies, Kasper reveals he is King Altair’s illegitimate son, sent to gather intelligence at the Forge. He explains that Magda was his spy, not King Silas’s, and that the crystal frog Ember gave Rune was a spying device. King Altair is coming to the palace to capture Rune’s mother, and Kasper intends to deliver both Rune and the Darkstone wand to his father.

Rune convinces Kasper to leave the bleeding Draven behind, arguing he needs Draven alive as leverage. When Draven goads Kasper about his orders, the prince summons his hidden ring-sword. Startled, Kasper’s hand jerks, slitting Draven’s throat before Draven’s blade severs Kasper’s fingertips. Kasper grabs the wand and flees as Felix, Ember, and Scorpius burst through the door.

Rune desperately channels the Empress, World, and Four of Swords to heal Draven’s near-fatal wound, guided by his mental presence. She manages to close his throat, leaving a scar. Meanwhile, Scorpius and Felix fight Kasper. When Kasper moves to stab Scorpius, Ember grabs his arm. Not realizing who holds him, Kasper shoves her against the wall and brings his knife down. Felix pushes Ember aside and takes the blade through his sternum.

Horrified at nearly killing Ember, Kasper escapes through a window. Draven tells Rune to save Felix, but the knife has pierced his heart. Despite her efforts, Felix dies in Ember’s arms as Rune’s Empress card burns out.

The rest of their friends arrive. An enraged Wynter leads the chase after Kasper while Rune follows. They catch Kasper with Magda and a Death Arcana user at a portal, but Kasper escapes just before Scorpius tackles the portal-wielder. Draven arrives with Ember, and Amaya opens a new portal. Rune, Draven, and their friends go through the portal to pursue Kasper toward the Sedah royal palace.

Emerging onto the palace lawns, the group spots Kasper fleeing toward the forest. Rune explains to her friends that Altair seeks her mother to force a cure for the Curse, which would give him leverage over all immortal kingdoms. Her friends pledge loyalty. The injured Draven enters the palace to warn King Silas and evacuate their families while Rune and the others prepare to fight.

King Altair and his seraph army materialize via lightning. Kasper delivers the Darkstone to him, and Princess Reva teleports away with Kasper through a wave of light. A brutal battle erupts. Rune sees her father, Riordan, among the seraphs and realizes he is bound by vows to fight. She and Wynter use Judgment to control some seraphs, but Altair overpowers them. Fable strains to freeze Altair with the Hanged Man before collapsing. Scorpius fights him but is battered.

Rune duels Altair using the Star and Sun, but he is far stronger. She mentally begs her father for help. He tells her to keep Altair distracted, then moves to strike from behind. Altair’s magic freezes Riordan mid-attack and runs him through with a sword. Enraged, Rune grabs the Darkstone wand from Altair’s belt and stabs him in the eye.

Commander Soto and the druid army arrive through a portal. The seraphs retreat, with Altair taking the Darkstone wand with him as they withdraw. Rune attempts to heal her father’s fatal gut wound, but he stops her, explaining that druid magic cannot save a seraph bound by vows. He blocks her cards to prevent her from burning herself out trying. Telling Rune he is proud of her and calling her by her childhood nickname, Riordan dies. His body entropies, reverting to his mortal changeling state. Draven rushes to Rune and holds her as she breaks.

The day after the battle, Rune attends her father’s funeral. Only Draven and their friends are present for the small ceremony, where passages from the mortal Book of Sorrows are read. Earlier that day, a larger public funeral had been held for the other fallen, including Felix. She learns that during the fight, the seraphs abducted her mother from the palace despite the guards Draven assigned. War between Sedah and Nevaeh now seems inevitable. If her mother creates a cure for the Curse, Altair will use it to force the druids and elves into his war against mortals. Rune blames herself for leading Altair to her mother and for her father’s death.

After the funeral, they return to their blood-stained Hearth to gather belongings before moving to the palace. Draven reveals what her father told him before the Alfheim trip: to care for Rune and that he hoped she would someday not need to be so brave. Draven’s throat scar has not faded. Seeing Rune’s despair, he reassures her they are not failures and vows to kill Altair and Kasper.

He offers her the Oathbreaker cup, giving her the choice to break all her vows and leave him if she wishes. Rune instead takes the forgotten engagement bracelet and puts it on. She declares they will destroy Altair, rescue her mother, and take the immortal thrones together. Draven drinks from the Oathbreaker, then offers it to her. She drinks, symbolically committing to their shared cause and future rule.