Onyx Storm

Onyx Storm (2025) is the third installment in the new-adult romantasy Empyrean Series by Rebecca Yarros. The series follows Violet Sorrengail, who joins the Basgiath War College to become a dragon rider but discovers dangerous secrets that upend her perception of her home kingdom, Navarre, and its politics. Onyx Storm picks up where Iron Flame left off and delves into the war against dark-magic wielders called the venin, who threaten the safety of everyone and everything Violet loves. After learning that her dragon Andarna’s breed—called the irids—might hold the key to permanently mending the protective wards on the Continent and defeating the venin, Violet and her squad travel beyond Navarre’s borders in search of answers while hunted by the venin who desperately want to claim Violet and her partner, Xaden, for their power.

This guide refers to the eBook edition published by Red Tower, an imprint of Entangled Publishing, in 2025.

Content Warning: The source material and guide feature depictions of graphic violence, sexual context, and illness/death. 

Plot Summary

The novel opens with a letter from General Melgren to King Tauri, reporting that General Sorrengail has died and suggesting an alliance with Poromiel. Meanwhile, Violet Sorrengail follows Xaden Riorson, who is now venin, though he has not channeled his power since turning. Violet is determined to find a cure, and Andarna suspects that finding the seventh breed of dragons, like herself, may hold the key to defeating the venin. Violet discovers Xaden speaking to Jack Barlowe, another venin, in his cell. Jack warns that Xaden will eventually lose control and drain her. To protect Xaden’s secret, Violet seeks out Imogen to erase Jack’s memory of their conversation.

Two weeks later, Violet meets with the Senarium, where they struggle to negotiate peace with Poromiel. Without her mother’s storm-wielding abilities, Navarre has been plagued by continuous storms, making it difficult to patrol for venin. Later, while visiting her friend Sawyer in the infirmary, Violet and her friends are interrupted when a cadet stumbles into the infirmary, screaming that everyone is dead. Venin have infiltrated the keep, disguised as scribes. Violet, Rhiannon, and Ridoc fight off an attack on Jack Barlowe’s cell, where Violet sees a silver-haired venin woman who promptly disappears before her eyes, knowing their mission to retrieve Barlowe has failed.

Violet is given a task force to find the seventh dragon breed and is forced to accept Captain Grady as her team leader. Meanwhile, Viscount Tecarus gives Violet three more days to uphold her end of a previous deal and negotiate an alliance with the gryphon fliers of Poromiel. Violet and her friends secretly commit treason to alter the wardstone, allowing gryphon fliers to use their lesser magics within the wards, allowing the alliance between Navarre and Poromiel to make headway. When sent to the Samara outpost with her fellow second-years as punishment, Violet and her squad decide to save a nearby town from a venin attack because one of their fliers has family there. In the town, Violet sees the silver-haired venin once again, who introduces herself as Theophanie. Theophanie wields what Violet assumes is lightning but is actually storms.

Meanwhile, Xaden is reinstated as Duke of Tyrrendor and given a seat on the Senarium. He is reassigned to the Eastern Wing, separating him from Violet. Determined to learn more about the irids, Violet retrieves her father’s research, hidden in her mother’s former rooms. The research points her toward Deverelli, an isle kingdom where her father instructs her to locate a merchant named Narelle Anselm.

Violet’s quest squad is led into a trap on their very first mission, which kills both Captain Grady and one of their squad members, Aura Beinhaven. With the captain’s death, Violet handpicks her next squad: Mira, Dain, Ridoc, Xaden, Cat, Cat’s cousin Drake, Prince Halden, and Halden’s guard, Anna.

The team travels to Deverelli where Halden meets with King Courtlyn, and the others search for Narelle Anselm. They find her in a bookstore, where Violet answers several questions to prove her intelligence. Narelle gifts her with six more books left by Violet’s father. When Xaden and Violet learn that Halden has gotten into trouble with King Courtlyn, they visit the palace. They discover Halden has conspired with his guard to steal back many items traded to Deverelli over the century and his guard, Anna, has paid the price with her life. When Courtlyn grows weary of them, he orders his guards to kill them all, prompting Xaden to channel and kill all the threats. Violet sends him back to Aretia to recover until his red-rimmed eyes return to normal. After gaining the upper hand by using Andarna’s appetite for Courtlyn’s panthers, Violet convinces King Courtlyn to allow them to use the palace as a base during their mission.

When Violet returns to Basgiath, her squad plans to search all the other islands for evidence of Andarna’s kind. Though their orders instruct them to return back home between each island, they mutually agree that will take too much time. They decide to break the rules and search all the islands at once before they return. In the meantime, Violet adds two gryphon fliers, Maren and Trager, to her squad.

They leave for Dunne, where Violet notes people with hair like hers serving at Dunne’s temple. Violet, Dain, and Xaden must fight champions to gain audience with the queen. Upon winning their challenge, the queen hears them out but cannot offer them the troops they request for the war. The squad moves on to the isle of Hedotis, where they meet with the triumvirate and realize Xaden’s mother is married to one of its members. The triumvirate attempts to poison them—and nearly succeeds in killing Garrick—but Violet’s wit saves his life. When they move on to the isle of Zehyllna, they are forced to play a strange card game where they must smile and thank their benefactors for their gifts, whether good or bad. The game progresses positively until Trager pulls an arrow card and gets fatally shot through the chest, which Violet must thank his killer for. The brutal game gains them an army of 40,000 to aid in the war against the venin.

When the group flies to a remote island to burn Trager and his gryphon’s bodies, the irids find them. They are disappointed with the weapon Andarna has become, calling themselves dragons of peace. Andarna is devastated not to have their approval, and Violet is disappointed to learn that they do not know a cure for venin, nor do they wish to aid in the war or re-power the Continent’s wards. Violet’s squad returns home unsuccessful. Violet finally shares the truth of Xaden’s affliction with her friends, revealing her primary dedication behind her search for a cure.

When Aretia comes under attack, the squad rushes to protect the city. Aaric tells Violet that protecting Dunne’s temple holds the key to Tyrrendor’s survival. Though she first ignores this advice, she ends up at the temple with Theophanie, who is forced to flee when the wards come back in full force. Leothan—an irid of Andarna’s kin—has come to the continent to recharge the wards before asking Andarna to return home with him to become educated in their ways. With Violet’s permission, Andarna breaks her bond with Violet and goes with Leothan, leaving Violet heartbroken.

Soon after, Mira is taken hostage by Theophanie, who requests Xaden, Violet, and Jack Barlowe’s presence. When they arrive Theophanie attempts to kill Jack, who apparently knows too much. She fails, and he is brought back to an interrogation cell in Navarre. Jack slits Mira’s throat, but she survives due to Brennan’s healing abilities, which are made stronger by Sloane Mairi’s ability to siphon extra magic from Dain into Brennan.

In the ensuing battle, Violet is aided by Aaric—whose signet is revealed to be pre-cognition. He provides her with a dagger she uses to kill Theophanie, but she is only afforded the chance when Xaden gives into channeling and becoming venin, releasing his shadows outward and killing off as many venin as possible.

A cliffhanger from Xaden’s point-of-view reveals that someone he trusted has also turned venin. Meanwhile, Violet returns to Riorson House and her brother 12 hours after the battle, with no memory of what occurred after she killed Theophanie. She has a wedding ring on her finger and a certificate detailing a legal marriage to Xaden, making her the Duchess of Tyrrendor. Violet realizes Imogen has erased her memories, but Imogen insists she only did what Violet asked of her.