An Ember in the Ashes recap

In the Martial Empire, where the conquered Scholar people are kept enslaved and illiterate, a young Scholar named Laia watches soldiers kill her grandparents and take her brother Darin for the drawings of Martial weapons hidden in his room. She runs, then bargains with Serra's Scholar resistance: they will free Darin if she spies on the commandant of Blackcliff Military Academy from inside the woman's household. At Blackcliff, Elias Veturius is days from graduating as a Mask and intends to desert, until the Empire's Augurs announce that the imperial line has failed and name him one of four Aspirants who must compete in supernatural Trials for the throne, alongside his best friend Helene and the brothers Marcus and Zak. The Trials cost the lives of Elias's friends. Laia is beaten, spied on and finally betrayed by the resistance leader who traded her away. The last Trial demands each Aspirant kill the one they love. Marcus kills Zak and takes the throne; Helene refuses and is made his Blood Shrike; Elias is condemned, then broken out by Laia. They flee north together to free Darin from Kauf prison, with Helene ordered to hunt them.

The Martial Empire conquered the Scholar people five hundred years ago and has kept them illiterate, unarmed and enslaved ever since. In the city of Serra, a Scholar girl named Laia lives with her grandparents and her older brother Darin. Soldiers led by a Mask, one of the Empire's silver-faced elite, break into the house at night; her grandparents are killed and Darin is dragged away for the drawings of Martial forges and weapons found in his room. Laia runs rather than fight, and the shame of it settles into her immediately. She makes her way to what is left of Serra's Scholar resistance, hidden in the catacombs beneath the city, and begs them to free her brother, trading on the fact that her dead parents once led them. Elsewhere in Serra, at Blackcliff Military Academy, the Empire's best student is counting down to graduation. Elias Veturius has been trained since he was six to become a Mask and has decided he will desert instead. Only two people complicate that plan: Helene Aquilla, his closest friend and the school's only female student, and the Academy's commandant, Keris Veturia, who is also his mother and has never treated him as anything but a subordinate.

The resistance names its price: Laia must go into Blackcliff as a household slave and spy on the Commandant herself, and only then will they move on Darin. She agrees, is marked as the Commandant's property, and discovers a household where mistakes are punished with mutilation. Two slaves take an interest in her: Izzi, a one-eyed girl who explains what survival there requires, and the kitchen woman known as Cook, who tells her to abandon hope. Her handler in the resistance is Keenan, a guarded red-haired fighter who works for its leader, Mazen. At Blackcliff's graduation, the Augurs appear. These red-eyed immortals announce that the imperial line has ended and that four Aspirants will be tested in Trials to choose the next Emperor: Elias, Helene, and the brutal twins Marcus and Zak Farrar. Refusal is not permitted, and Elias's plan to walk away collapses in a moment. The Augur Cain speaks to Elias privately in promises about freedom that he cannot decipher.

The first Trial, Courage, sends the Aspirants into the dark beneath the mountains to face what frightens them most. Elias is shown visions of himself as a mass killer, a future he believes the Empire is shaping him toward, and comes out badly shaken. Above ground, Laia's spying produces almost nothing the resistance can use, and the pressure from both sides increases: the Commandant beats her, and Mazen threatens to abandon Darin if she brings back nothing more. Elias and Laia cross paths in the Academy's corridors, and he steps in when Marcus corners her, an act neither of them can explain to themselves. Laia also learns the truth about her brother from Spiro Teluman, a Martial swordsmith who quietly stopped serving the Empire: Darin was his apprentice, learning the secret of Martial steel so that Scholars might one day be able to arm themselves. He was not a traitor.

The second Trial, Cunning, strands the Aspirants far from Serra and requires them to get back inside Blackcliff, hunted the whole way by the supernatural creatures that live in the Empire's wild places. Elias and Helene work as a pair and survive it, and the closeness it forces on them brings Helene's feelings for him into the open, which he cannot return in the way she wants. Marcus and Zak return as well. Inside Blackcliff, Laia's position worsens; the Commandant is increasingly attentive to her, and Laia glimpses her mistress in conference with a figure that does not appear to be human. Keenan begins meeting Laia more often than the mission strictly requires. The Aspirants are told the remaining Trials will not be survivable by all of them.

The third Trial, Strength, is fought in front of the school: each Aspirant is given command of soldiers and ordered into a pitched battle against the others, with no allowance made for the fact that the combatants are classmates. Several of Elias's friends are killed, one of them by Marcus personally, and Elias is left with the exact outcome the Trial of Courage had shown him. The Empire treats the deaths as an administrative matter. Meanwhile Laia finally extracts what the resistance wanted, and learns in the process that Darin is being held in Kauf, the Empire's prison in the far north, from which nobody is released. Mazen shows no intention of mounting a rescue that distant, and Laia begins to understand that the bargain she made may have been worthless from the start.

At the city's Moon Festival, Elias and Laia agree to run: he will desert and take her north to Kauf for Darin. The Commandant is waiting for them. Elias is seized and condemned to death for desertion, and Laia is beaten and returned to the household. The betrayal is traced back to Mazen, who traded Laia's identity to the Commandant in exchange for what he wanted and never had any plan to free Darin. Keenan and Sana break with him. Izzi and Cook, who have both spent their lives avoiding exactly this kind of risk, commit themselves to getting Laia and Elias out of Serra. In the death cells, Elias is visited by the Augur Cain and by his mother, and is given nothing he can use.

The last Trial is Loyalty, and the Augurs order each Aspirant to kill the person they love most. Marcus kills his twin brother Zak and is crowned Emperor of the Martial Empire. Helene, ordered to execute Elias, cannot do it; Marcus takes her as his Blood Shrike, second in the Empire and bound to his service, with her family's lives as the guarantee. Elias is brought out to be executed and is rescued instead: Laia, Izzi, Keenan and Cook get him off the block and into the catacombs, and the four of them escape Serra. Laia now knows Darin is alive in Kauf, and the group turns north to free him. Marcus's first order to his new Blood Shrike is to hunt Elias down and kill him, which means Helene must pursue the person she has just refused to murder. Keris Veturia keeps Blackcliff, her ambitions and her inhuman ally, and Elias leaves the city carrying a poison administered to him in the cells that none of them yet knows about.

The final Trial is Loyalty: each Aspirant is ordered by the Augurs to kill the person dearest to them. Marcus kills his twin Zak and is crowned Emperor. Helene cannot bring herself to kill Elias, and Marcus binds her to him as his Blood Shrike, the second in the Empire and his personal enforcer, holding her family's safety over her. Elias is condemned and taken to the execution block, but Laia, Izzi, Keenan and Cook engineer his rescue, and he escapes Serra through the catacombs with them. Laia has learned that the resistance leader Mazen sold her to the Commandant and never intended to free Darin, and that her brother is alive in Kauf, the Empire's northern prison. She, Elias, Izzi and Keenan set out for it, a journey of months across the Empire. Helene's first order from her new Emperor is to hunt Elias down and kill him. Keris Veturia keeps her command of Blackcliff and her own unexplained plans, including the shadowed figure Laia once glimpsed her meeting. Elias leaves Serra carrying the poison his mother saw administered to him in the death cells, which nobody in his party yet understands.