Iron Flame (2023) is the second installment in The Empyrean Series by Rebecca Yarros. A new adult romantic fantasy saga, the series follows Violet Sorrengail as she endures the brutality of Basgiath War College, a fantastical but sinister educational institution, and uncovers secrets long hidden by the kingdom of Navarre’s leadership about the ongoing war against dark magic-wielders of folklore called venin. Iron Flame explores themes such as the conflict between loyalty and moral duty and the conquering power of love. Yarros is also the author of several standalone novels, including The Last Letter (2019) and The Things We Leave Unfinished (2021).

Yarros is a seasoned author of contemporary romance novels. The first book in The Empyrean Series, Fourth Wing, became an overnight sensation on social media upon its release. The Empyrean Series reached #1 on the New York Times, USA Today, Sunday Times, and Wall Street Journal bestseller lists.

This guide refers to the hardback edition published in 2023 by Red Tower Books, an imprint of Entangled Publishing.

Content Warning: The source material includes depictions of physical abuse and graphic violence/death.

Plot Summary

Iron Flame opens immediately following the concluding events of Fourth Wing (See: Background).

In the aftermath of an attack by venin (dark magic-wielders) on the military outpost of Athebyne during the end-of-year War Games held at Basgiath War College, Violet recovers from her injuries in Aretia, a town in the kingdom of Navarre’s Tyrrendor Province. Over the past three days, her world has been upended. Xaden Riorson, the third-year she has fallen in love with, is part of a secret rebellion thought to have ended years ago. Some of Violet’s fellow students survived Athebyne with her and are also part of the rebellion. Violet’s brother, Brennan, who she thought died fighting the rebels six years ago, is alive and the rebellion’s leader. And the venin from her father’s folktales—wielders of dark magic who draw power directly from the earth and ride wyvern, which they create and control—are real and intent on killing everyone on the Continent. Navarre's leadership has carefully hidden all of this and erased it from history to protect the citizens within the kingdom’s magic wards, which keep the venin out.

Brennan and Xaden prefer to keep Violet in the dark about the details of the rebellion until she can properly use her magic to make a mental shield and block out her former friend, Dain Aetos, who can read memories. Violet distances herself from Xaden until he agrees to be fully honest with her. Andarna, one of Violet’s two bonded dragons, is taken to the Vale for the Dreamless Sleep—a critical process during which young dragons develop into adults—while Violet, Xaden, and their peers are sent back to Basgiath for graduation. Colonel Aetos, who sent them to die after Dain stole Violet’s memories, threatens the lives of their families and friends if they tell anyone about the venin. Dain unsuccessfully attempts to reconcile with Violet, oblivious to what really happened in Athebyne and unaware of the depth of his betrayal. Xaden graduates from Basgiath and is sent to Samara, a border outpost. He and Violet are given leave on alternate weekends to visit one another so that his dragon, Sgaeyl, and Violet’s dragon, Tairn, can satisfy their mating bond.

As her second year at Basgiath War College begins, Violet is excluded from working with the rebels to smuggle alloy daggers from Basgiath’s forges to the gryphon fliers of Poromiel, the nation which lies undefended outside the wards that protect Navarre from venin. Major Burton Varrish replaces Colonel Aetos as vice commandant of Basgiath and targets Violet, punishing her whenever Andarna fails to show up for flight maneuvers. On Conscription Day, Violet’s old friend, Prince Cam, crosses the parapet and joins Violet’s squad under the pseudonym Aaric Graycastle. As the year gets underway, Athebyne survivors begin dying one by one at the hands of Colonel Aetos’s assassins. Unable to lie to her friends, Violet distances herself to protect them and instead enlists her scribe friend, Jesinia, to aid in her research into the First Six who raised the wards. Violet keeps this secret from Xaden, who still refuses to share information with her.

For the second-year Rider Survival Course (RSC), Violet and her friends must complete joint land navigation exercises alongside a team of infantry, scribes, and healers. They fail. A signet-blocking elixir cuts the riders off from their dragon bonds and signet powers. Violet becomes increasingly angry in class when venin attacks are hidden by their Battle Brief professor. Xaden discovers Violet has been researching the wards and they fight about the one-sided trust he expects from her.

It becomes more difficult to keep the truth from her sister Mira and her best friend Rhiannon as time goes on. Violet decides to tell Rhiannon about Dain’s signet and the fact that her fellow Athebyne survivors are being killed off for something they witnessed. Aaric reveals to Violet that he knows the truth about the venin and, unlike his father King Tauri, he wants to do whatever he can to fight them. Eventually, Violet and her friends are seized for another RSC challenge: interrogation. Varrish uses the opportunity to pry information from Violet, even attempting to use Dain’s signet, but his efforts are unsuccessful.

Jack Barlowe, whom Violet believes she killed with her lightning power the previous year, has secretly been healed and returns to class. Violet hears that Xaden has been badly injured in a gryphon attack on Samara and deserts her post to visit him. She finds him completely healed at Samara and he extends more trust to her by bringing her with him to deliver smuggled daggers to gryphon fliers—one of whom is Catriona “Cat” Cordella, an ex-girlfriend of Xaden’s. Xaden gifts Violet an alloy dagger to protect herself against venin, but when Violet returns to campus, Varrish arrives to check her person before she can stash it elsewhere. Rhiannon teleports the dagger to her room with her signet power, but that forces Violet to reveal everything to Rhiannon and her other friends, Sawyer and Ridoc.

The group devises a plan to break into the sublevel vault of the Archives and steal the journals of the First Six. They locate two journals belonging to the first six: Warrick’s and Lyra’s. While Xaden leaves Basgiath with Warrick’s journal, Nolon, the healer, catches Violet with Lyra’s and turns her into Varrish who tortures her for days. Only the visions Violet has of her dead friend, Liam Mairi, get her through the ordeal without breaking. Dain is brought in to read her memories, and Violet shows him everything, prompting him to kill Varrish and help her escape just as Xaden arrives to save her. Together, they reveal the truth to all of the students at Basgiath and allow any cadets who wish to desert to return with them to Aretia. Violet and Xaden bring over 200 riders and dragons to Aretia, where Andarna wakes from the Dreamless Sleep. Mira soon arrives in Aretia with many more riders after their mother, General Sorrengail, tells everyone the truth and gives them the choice of whether to desert or stay.

An Assembly member named Felix teaches Violet to control her lightning, which has become uncontrollable and dangerous. Violet translates the warding ritual in Warrick’s journal but her first attempt to raise Aretia’s wards fails. Against Xaden’s wishes, she leaves for Cordyn with Mira and Brennan to convince Viscount Tecarus, a potential ally to the rebels, to give them the luminary to power Aretia’s forges and make alloy daggers. Xaden is already there when they arrive, and Violet discovers Cat is Tecarus’s niece and Xaden’s former betrothed. Violet wields her lightning to kill a venin in exchange for the luminary from Tecarus, who also requires they take 100 gryphon fliers with them to Aretia for training. For several weeks, riders and fliers undergo several challenges to facilitate teamwork and trust between each other. They are also taught to weave Tyrrish runes, which can place magic for specific uses into objects to be used at later dates. During an exercise where teams of fliers and riders compete to locate runes hidden along the Esben Mountains, Violet’s group is attacked by Varrish’s dragon, Solas. One rider is killed in the attack, but Andarna kills Solas to protect the rest. Cat and Violet eventually put their differences aside and engage in a tenuous alliance.

Violet continues to retranslate Warrick’s journal, this time enlisting Dain’s help. Dain corrects the errors in Violet’s former translations, and she discovers a new way to raise the wards using dragon fire from all six dragon dens. Violet prevents a wyvern attack by successfully enacting Aretia’s wards, but they prove faulty. Violet discovers Xaden has a secret second signet, which allows him to read people’s intentions before they act. Violet and the Assembly are summoned to meet with General Melgren and General Lilith Sorrengail (Violet’s mother). Melgren, who can see future outcomes, foresees venin overtaking Navarre’s Samara outpost and asks Aretia for aid, which is denied by Brennan. General Sorrengail is shocked that Brennan is alive and hands over Lyra’s journal, believing Violet will translate it and discover the proper way to activate the wards.

Xaden and Violet begin to mend their relationship after agreeing to be more truthful with one another. Jesinia begins translating Lyra’s journal. Violet realizes that the venin gathering outside Samara are a distraction and that someone inside Basgiath intends to take down the wards. Violet and her supporters fly to defend Basgiath against the advice of Aretia’s Assembly. By the time they arrive, Jack Barlowe—who reveals himself as a venin—has already destroyed the wardstone, bringing down the wards. With nearly all its forces pulled to Samara, General Sorrengail works alongside Basgiath’s present leadership to devise a battle plan against the approaching wyvern hoards. Violet’s squad is tasked with guarding the area surrounding the wardstone while Brennan attempts to mend it with his signet power.

When the battle begins, Violet wields her lightning to protect her squad. Sawyer loses a leg to a wyvern bite. While delivering him to the healers on ground level, Violet is attacked by several venin, but saved by Andarna, who breathes fire for the first time. Jesinia finds Violet to deliver the newest translation of Lyra’s journal, which records seven dragon dens needed for the ward ritual. Violet realizes Andarna, with her oddly colored scales that allow her to camouflage so well, is from the seventh den. As Violet gathers the seven dragons needed for the ritual and begins imbuing the newly mended wardstone with power, Xaden continues to fight on the battlefield, where he confronts the venin Sage who has been stalking his dreams. To kill the Sage and save Violet’s life, Xaden channels power from the earth and turns venin. Violet realizes that the wardstone will require all her power to work, which will kill her, but General Sorrengail sacrifices her life instead. The dragons activate the wardstone with their fire, which causes the venin to flee after the wyvern drop dead. After the battle, Violet finds Xaden and discovers he has turned venin.