Crowntide

Published in 2025, Crowntide is the fourth novel in the #1 New York Times bestselling romantasy series The Lightlark Saga by Alex Aster. Aster gained significant attention for the series after a viral video she posted on TikTok, a social media platform, led to a major publishing deal and established her as a prominent author in the #BookTok community. The Lightlark Saga began with Lightlark (2022), followed by Nightbane (2023) and Skyshade (2024). Crowntide picks up immediately after its predecessor, with protagonist Isla Crown having sacrificed herself to save her world by trapping her immortal ancestor, Lark, in another realm. This act forces her two lovers—and mortal enemies—Oro Rey and Grim Malvere into a strained alliance to find and rescue her.

The novel explores themes common to the romantasy genre, including the tension between fate and free will. Isla’s journey is shaped by a prophecy that forces her into impossible situations, yet she remains determined to forge her own destiny. The narrative examines Love as a Force of Both Creation and Destruction, as the characters’ powerful emotions create alliances, fuel destructive impulses, and alter the course of their world. Additionally, the story delves into The Corrupting and Isolating Nature of Immense Power through its antagonists and the immense burdens placed on its heroes. Another central theme is Confronting the Past to Reshape Identity and Future, as Isla, Oro, and Grim must all grapple with their personal histories and memories to navigate their present crises.

This guide refers to the 2025 Amulet Books edition.

Content Warning: The source material and this guide contain depictions of child abuse, graphic violence, physical abuse, emotional abuse, sexual content, cursing, child death, and death.

Plot Summary

Isla Crown is one of the rulers of a fantasy world called Lightlark. She reigns over the Wildling and Starling peoples. Her world is under attack from Lark, her immortal ancestor and one of Lightlark’s original three founders. Isla opens a portal to Skyshade, the home realm of Lightlark’s founders, pulls Lark through with her, and seals the portal behind them. Isla’s self-sacrifice devastates her two lovers—Oro Rey, ruler of the Sunling realm and king of all Lightlark, and Grim Malvere, Isla’s husband and the ruler of Nightshade. Grief-stricken, Grim attacks Oro. They are unable to use their powers because they are in a magical maze, so they engage in brutal hand-to-hand combat until Grim holds a blade to Oro’s throat. Instead of killing him, Grim questions Oro’s love for Isla and declares his own intention to rescue her. Proposing an alliance, he states he loves Isla more than he hates Oro. Despite centuries of enmity, Oro agrees.

At his winter castle, Grim meets with Oro and his friends. Each realm is associated with particular supernatural powers. For example, Grim can use shadows as weapons because he is from Nightshade. In addition, certain individuals possess special abilities called flairs. Grim’s flair allows him to create portals, but it’s not strong enough to cross worlds. He reveals that he gave Isla a necklace containing Infinite, a mythical black diamond of immense power, and that his life is magically bound to hers, a temporary measure that he used to save her when she died saving him from monsters called dreks. A flashback details the trials Grim endured to claim the diamond, culminating in him declaring his love for Isla to be “infinite.” Meanwhile, Isla and Lark arrive in Skyshade, a desolate world of ash where their powers are suppressed. They are captured by desert scavengers.

Oro and Grim seek the help of Cleo, the ruler of Moonling. She admits that she knew Isla planned to sacrifice herself to bring Lark to Skyshade. Isla absorbs the powers and spirits of everyone she kills, and Cleo hopes that Isla will be able to resurrect her deceased son if Isla kills Lark and absorbs Lark’s regenerative flair. Cleo reveals prophecies of a coming war between worlds called “Crowntide” and gives Grim and Oro a magical compass leading to a lost king who is believed to know more about the future.

The compass leads them to a remote isle where Cleo parts the sea, revealing an ancient underwater prison. Miles below the surface, hundreds of monstrous prisoners are trapped in an eternal cycle of drowning and reviving, their powers nullified by shackles made of an enchanted metal called “shademade.” Grim and Oro fight their way through the prison, their old animosity resurfacing in arguments about their past and their love for Isla. They find the lost king, who reveals he has foreseen their arrival. He calls Isla a “Worldkey” and explains that Cronan, Grim’s ancestor and one of Lightlark’s three founders, needs Isla’s combination of powers and the Infinite diamond to conquer the universe. The lost king gives them the Threads of Time, a powerful artifact, before vanishing. As Cleo’s power wanes, Oro and Grim fight their way back to the surface, saving each other’s lives and solidifying their truce.

In Skyshade’s ash desert, a magical storm restores Isla’s and Lark’s powers. The scavengers flee, and Lark attacks Isla. Their duel is interrupted by mysterious knights wielding a void-like energy that drains their abilities. Overwhelmed, Isla grabs Lark and escapes through a small portal. They land in the Forgotten Forest, a place that forces them to relive their past. Isla is plunged into memories of her cruel childhood, which she spent training in isolation for the Centennial, a deadly competition between Lightlark’s rulers. A mysterious silver-haired woman saves her from an attack and takes her to a grove containing the Pool of Possibilities, which can show alternate timelines. The woman vanishes as Cronan arrives, effortlessly defeats Lark, and captures both her and Isla.

Cronan takes Isla to his castle and begins a daily routine of mental torture, using shadow magic to break into her mind and reshape her memories with the goal of turning her into a weapon who will help him conquer the universe. To protect Oro and Grim from Cronan, Isla severs the magical bonds connecting their souls. On Lightlark, Oro and Grim are devastated when they can no longer feel her, but Isla discovers she can still communicate with them in their dreams. Aided by a vision of her younger self, Isla builds a mental fortress to resist Cronan. Meanwhile, Oro and Grim visit the “cursed world” with the Skyling ruler, Azul, where they encounter the souls of deceased relatives. They learn from Azul’s husband about a sacred pool on Lightlark linked to one in Skyshade. They find the pool, but Grim’s power alone cannot create a portal.

Oro becomes dangerously obsessed with the Threads of Time, losing himself in the past for days until his friends intervene. Together, Oro and Grim use the threads and Grim’s flair to travel to the past, where Oro’s ancestor, Horus, tells them about the components for a stable portal: massive energy, a living piece of Skyshade, and the combined power of Sunling, Nightshade, and Wildling rulers. With help from their allies, Grim and Oro retrieve Isla’s lost storm ring, which contains a piece of Skyshade, and recruit Cinder, a powerful young Starling, to provide the energy. In her mind, Isla visits the Pool of Possibilities, where she sees that her past “mistakes” actually prevented greater catastrophes. She speaks with the soul of her former friend, Aurora, who tells her Cronan’s power is tied to a hidden object. Grim discovers the shape of Cronan’s personal skyre, a symbol granting immunity to his power-dampening field, is the maze in his garden and carves it into his arm.

After weeks of torture, Isla formulates a plan. She allows Cronan into her mind but uses the connection to learn his weaknesses and take his crown, the object his power is bound to. The silver-haired woman reveals an ancient concept of “fated matches” and explains that Isla’s soul is the first to be bound to two other souls. The prophecy dictates one of the three must die. Isla has an opportunity to look into the future and see the potential outcome if she chooses to kill Grim or Oro, but she refuses. Isla chooses Grim over Oro and re-establishes her bond with him, pulling him through the portal to Skyshade. Cronan retaliates by permanently erasing Grim’s memories of Isla and severing their bond. He convinces the amnesiac Grim that Isla is an enemy. On Lightlark, Oro’s heartbreak causes his powers to erupt violently, while the unstable portal unleashes monstrous creatures onto the island.

Grim hunts Isla across Skyshade. They engage in a series of duels, during which glimpses of his memories with her confuse him. He captures Isla and brings her back to Cronan. Imprisoned again, Isla attends dinners with Cronan’s council and attempts to convince Grim of their love story, leading to several charged encounters that leave him conflicted. To prove her supposed newfound loyalty to Cronan, Isla publicly kills a woman who had helped her while she was hiding from Grim, secretly hoping to resurrect her later. Grim witnesses her act and later hears her crying, realizing it was a façade. He begins to doubt Cronan.

Isla brokers a deal with a wounded Lark. Her ancestor agrees to give Isla some of her blood to heal Grim’s festering skyre in exchange for the return of Lark’s feather, which contains some of Lark’s power and is in Grim’s possession. After healing Grim, Isla steals the feather from a sleeping Lark. She convinces Lark to let her kill her by claiming that an alliance between the two of them is the only way to stop Cronan and by promising to bring Lark back. Isa kills Lark, absorbing her power of regeneration and becoming unkillable. However, she doesn’t bring Lark back from the dead. Using the feather, she carves Cronan’s skyre into her hand, permanently regaining her powers. She breaks out of her cell and lures Grim to the Forgotten Forest, forcing him to relive their love story. He is on the verge of remembering her when Cronan arrives. Cronan threatens Grim, forcing Isla to lead him to the Pool of Possibilities. There, Cronan learns how to correct his past mistakes to find a key and then breaks Isla’s neck.

Isla resurrects herself and battles Cronan. He traps her at the bottom of the pool, but she breaks free, seizes his crown, and takes his power. Grim, seeing all possible futures in the pool, realizes he will die if he sides with Isla. He betrays her to save himself, stealing Cronan’s crown and attempting to imprison her. In that moment, Isla portals herself and the pool away. She arrives back on Lightlark and reunites with Oro, telling him of Grim’s betrayal. Just then, portals from Cronan’s conquered worlds open in the sky, beginning the Crowntide war. The story ends with the revelation that Isla, Oro, or Grim, must find the Heartblade, a legendary weapon that can kill Cronan permanently.