***The following spoils the main plot of Wither Thorn. Proceed at your discretion.***
Caia Blackthorn is the younger of two sisters and next in line to inherit the famed yet feared magic of “soul raising”–also known as necromancy. Unlike the other three houses of magic (naturalism, purification, and charming), only one blood line in existence will produce raisers. Their powers manifest on their sixteenth birthday.
In the country of Noverim, its king holds captive the only known line of soul raisers, the Blackthorn family. On her sixteenth birthday, Caia Blackthorn dreads the awakening of the accursed magic inside her.
However, something’s wrong. Caia’s magic hasn’t manifested by the end of the day, and she fears her only remaining family, her capable older sister Lavine, is being punished for her failure when Lavine is called to the castle dungeons.
What she discovers there is a secret too disturbing to stomach–Lavine has been torturing King Arcturus’s enemies. Caia discovers that the king plans to use both of them as instruments of war, as soldiers and torturers.
However, as Caia learns, Lavine’s compliance to the king is a cover for her secret plan to allow both of them to escape the castle. Lavine made a promise to their deceased mother to get them out of the castle. They flee as the castle guards and King Arcturus pursue them. Lavine duels with one of the king’s generals to buy them more time.
To fulfill her promise, Lavine sacrifices her freedom for Caia’s. She is left behind while Caia escapes to a camp of war refugees squatting outside the Royal Capital. This is when Caia’s powers finally manifest, and she can hide it no longer–she is a necromancer.
Caia finds allies in a refugee of war gifted in purification magic (Galen) and a defected soldier harboring a dark secret and a smart mouth (Rigel), and together they journey to the neighboring country of Llyra for safe haven while avoiding the spies and soldiers sent by the king to capture Caia.
On their way there they arrive in Raien, a city illuminated at night by naturalist flames. Caia learns her sister is going to appear at a masquerade ball inside the city, and the three make plans to infiltrate the party using disguises to save Lavine.
During the night, Caia and the healer Galen, disguised as a servant, share a kiss. They break away when Caia notices it’s nearly time for her sister’s appearance.
Galen is harassed by a war general and other soldiers who believe him to be a serving boy. Galen recognizes the danger these men pose. With his knowledge of medicinal plants, he decides to dose the wine of some of the masked soldiers and guests.
The dosed masqueraders begin dropping to the floor when a figure appears on the balcony. Caia rushes to get a message to her sister, but it’s a trap.
Using the forbidden magic of mind control (a type of charming magic), King Arcturus captures Caia and forces her to raise macabre dancing skeletons as a show of his power.
Rigel forces Galen to flee the masquerade with him as they fight off the undead. They leave the city for the most likely place where the king has taken Caia–the brutal prison known as Ulun-dur.
Ulun-dur is a dark tower deep in the southern deserts. Caia learns from a fellow prisoner (her mother’s midwife), that her deceased mother lied to everyone about the date of Caia’s true birthday because of a prophetic dream. Her mother hoped for Caia to leave the castle before she turned 16 and gained full use of her magic.
Although Rigel and Galen try to break Caia out of Ulun-dur, a mystery party gets there first. Nocturni, beings living in the southern deserts who drink blood and devour corpses for sustenance, believe Caia is their prophesied savior.
Caia, Rigel, and Galen break free of the Nocturni, but on one condition–Caia has promised her servitude at a later date to a Nocturn named Soren.
Just before they reach the walls of Llyra, the Nocturni ambush them in the desert. This leaves Galen near-death, and Rigel has been bitten.
As they cross the desert in low hopes, Caia and Rigel piece together their histories (Rigel’s past as a soldier and Caia’s experience at the masquerade), and they realize that the king of Noverim secretly possesses charmer magic. The king uses it to control the minds of others, like those of the soldiers in his armies.
When Caia finally crosses the border from Noverim to Llyra, she reveals King Arcturus’s secret to the minister of Llyra in hopes that he can stop the evil king’s conquest.
The minister agrees to help, but only if Caia aids in the upcoming skirmish between Llyra and Noverim’s armies.
In the Battle of Sandstorms, Caia uses her knowledge of King Arcturus’s magic to temporarily sever his mind’s control over his own soldiers, thus exposing him as a charmer to everyone on the battlefield.
For now, Llyran forces have staved off Noverim’s looming invasion.