Thorn Season

In the kingdom of Daradon, a 200-year-old law known as the Execution Decree mandates the slaughter of Wielders, people born with an invisible extension of power called a specter. The decree is enforced by the Capewells, a vast family of masked executioners called Hunters who possess a Spellmade compass capable of tracking Wielders. Alissa Paine, the 18-year-old daughter of Lord Heron Paine, the ruling lord of the province of Vereen, is secretly a Wielder. Her birth mother, a Wielder named Darcy Calloway, was Hunted weeks after Alissa's birth, leaving Alissa only a small lucky coin as a memento. Alissa has hidden her specter from the Hunters, who are also her relatives through her father's maternal line.

On the first morning of Rose Season, an annual social and political season at court, Alissa and her best friend, Tari, a Bormian immigrant, scrub a Hunters' Mark from the door of their recently captured friend Marge. The Huntings have increased sharply, with 10 occurring in two months, filling Alissa with dread.

At the opening ball in the capital city of Henthorn, Alissa encounters Garret Shaw, her former best friend and an adopted member of the Capewell family who chose the Hunters over her seven years earlier. Briar Capewell, the head of the Hunter family, confronts Alissa's father about an Ansoran ambassador arriving at court. King Erik Vard dances with Alissa and makes his romantic interest clear. News arrives of a mass Hunting at the Jacomb estate, where 24 staff members have been killed.

That night, four masked intruders kidnap Alissa from the Paine estate. She awakens in underground tunnels and discovers her captors are Wielders led by a man named Keil, who claims the Capewells stole something from him. He has ordered Alissa's father to retrieve Wielder prisoners from Capewell Manor as ransom. At the exchange, Garret delivers a wagon containing five Wielders held in dullroot, a specter-suppressing poison. Alissa is shaken to learn the Capewells have been imprisoning Wielders.

At Capewell Manor, Garret reveals that Alissa's father locked an oath band, a steel bracelet binding its wearer to silence, on Garret's wrist seven years ago. Heron forced Garret to push Alissa away so she would never discover that Heron had been providing names of suspected Wielders to the Hunters. Heron believed the arrangement let him control which Wielders were targeted and protect Alissa. Garret also reveals that his adoptive father, Wray Capewell, was murdered and the compass stolen seven years ago. A palace key with a rose engraving was found near the body, and copycats have since used the compass for increasingly brutal Huntings. He proposes that Alissa join court to investigate which noble stole the compass, leveraging Erik's interest as cover. Alissa agrees but privately resolves to keep the compass for herself.

Alissa confronts Heron, who insists he acted to protect her, then departs for the palace. She reunites with Princess Carmen Vard, Erik's cousin and heir presumptive, and meets Lady Perla Byrd, a seemingly timid noblewoman. Alissa is stunned to discover that Keil is the Ansoran ambassador, operating under diplomatic immunity to rescue his sister, who was captured by the Capewells. She secures a future favor from Keil in exchange for her silence about his true identity.

Alissa tests the silver key from the murder scene and discovers it opens Carmen's suite, which once belonged to Carmen's exiled mother, Lady Nelle. Inside, she finds shipping documents. She discovers that Carmen is secretly involved with Dashiel, one of Keil's Wielders. A copycat operative attacks Alissa in her chambers, warning her to stop searching. She stabs him with his own eurium knife—eurium being a rare metal capable of incapacitating Wielder specters—but cannot kill him, paralyzed by memories of the Opal, a day four years earlier when she witnessed Erik's guards torture a sympathizer to death. She traces the knife to a bladesmith who disappeared after delivering weapons to coordinates in Vereen.

At Budding Ball, Keil shows Alissa his specter and wraps it around her hands, and they nearly kiss. Erik escalates his courtship, reveals a secret room containing a commissioned portrait of Alissa wearing the royal crown, and proposes to make Alissa his co-ruling queen. Alissa's father visits and shares the story of her birth mother for the first time. Shortly after, Alissa returns to Vereen and discovers Heron's body in his study, his heart cleaved open. Her specter erupts, destroying the room. At the funeral, Briar pressures Alissa to join the Hunters, and Alissa slaps Briar. When her copycat attacker returns, Alissa kills him with her specter.

Garret confesses that he orchestrated Alissa's kidnapping to leverage Heron into unlocking his oath band, and Alissa rejects him. She and Tari descend into mining tunnels and discover a Wielder prison with shackles, bloodstains, and dullroot dispensers. Keil reveals that Carmen has been helping smuggle vulnerable Wielders out of Daradon in exchange for support of her claim to the throne. Alissa demands that Keil translate a swirling symbol found on the copycats' weapons and prison walls, as repayment of his debt.

At a court event, Erik orders a minister tortured for presiding over a funeral for executed Wielder employees. Alissa's control snaps and her specter strikes Erik, launching him across the ballroom. Keil claims responsibility and flees, briefly taking Alissa as a hostage before releasing her at the palace gates. At Emberly River, their specters intertwine and they share their first kiss. Keil asks Alissa to come to Ansora, but she refuses. Alissa learns that Keil is a grandson of the former Ansoran emperor. Keil's translation of the copycats' symbol arrives: "Gods cannot stand alone," the exact words Erik used when proposing.

Garret discloses that Briar murdered Heron after discovering his research on destroying Spellmade objects. Briar deploys a dullroot canister, and Alissa awakens chained in a dungeon. Over 12 days, Erik reveals the full truth: He murdered Wray Capewell at 15, stole the compass, and has orchestrated the copycat Huntings, building underground prisons for experimental trials on captive Wielders. He has known Alissa is a Wielder since she was 14, when he watched her mercy-kill the tortured sympathizer at the Opal with her specter. The compass, he explains, points to specters themselves, and he intends to exploit that power for conquest.

Perla rescues Alissa with specialized lockpicks, revealing she has known Alissa is a Wielder since Erik's coronation. Alissa retrieves the compass from behind her own royal portrait in a secret room, but Erik intercepts her. A chase through palace passageways ends in the kitchens, where Erik pins her against the wall. The dullroot has worn off, and Alissa spins her mother's coin with a feeble specter tendril to distract Erik, then stabs him in the back. Briar intercepts her at the gates, but Garret tackles Briar, and Alissa escapes.

After two days in Avanford, Alissa boards Carmen's Ansoran-bound ship carrying over 100 Wielders liberated from Daradon. She discovers the compass dome is made of dayglass, a material native to Ansora, and resolves to finish her father's research on destroying it. Erik has survived her attack. In an epilogue from Marge's perspective, Marge is revealed to be alive, imprisoned in Erik's new facility, where the king conducts experimental trials on captive Wielders, cutting them with different metals to study their specters. The story continues in subsequent volumes.