Published in 2025, Alex Aster’s Grim and Oro is a companion volume to her Lightlark series. It contains two novella-length romantasies (novels that marry romance with fantasy), retelling and expanding key events from the saga. Each half of the book is told from the first-person perspective of one of two rival rulers, Grim and Oro, who are both bound to Isla and to curses that threaten their realms. By splitting the story into “dark” and “light” halves, Grim and Oro questions the categories of “hero” and “villain” and delves into themes of The Clash Between Duty and Desire, The Uncertain Boundaries Between Heroism and Villainy, and The Impact of Trauma on Relationships.

This guide is based on the e-book edition released by Amulet Books in 2025.

Content Warning: The source material and this guide feature depictions of bullying, physical abuse, emotional abuse, child abuse, child death, death by suicide, substance use, graphic violence, sexual content, illness, and death.

Plot Summary

The world of Lightlark consists of six distinct peoples, each with their own ruler, and magic and unique curse that afflicts its members. These realms are Sunling, Moonling, Starling, Skyling, Wildling, and Nightshade. The first novella is told from the perspective of Grim, the ruler of Nightshade. When Grim is a child, his father pits his offspring against each other in an attempt to produce a powerful successor, and the boy is forced to kill his sister, Laila. To shield himself from his grief, Grim compartmentalizes his emotions and becomes a ruthless warrior who leads his father’s armies against Lightlark. After his father kills the Sunling king and queen who rule Lightlark, Grim is taken as a prisoner of war. During his captivity, he befriends Oro, a Sunling prince. Their friendship is broken when Grim unknowingly helps the Starling ruler, Aurora, cast deadly curses on all six realms. Grim escapes back to Nightshade and inherits the crown from his dying father.

Almost five centuries later, Isla, the Wildling ruler, accidentally teleports herself into Grim’s castle using a device called a starstick. She disguises herself as one of Grim’s consorts to evade his guards, and she stabs him when he kisses her. Grim is furious at Isla and himself for his attraction towards her, but he’s unable to shake his fascination. Grim realizes that Isla is the daughter of his former general, whom he entrusted with finding Cronan’s sword. This legendary weapon would allow him to control the dreks, winged monsters that are attacking Nightshade.

Grim requests Isla’s help in his search for the sword, and she agrees because she hopes that an alliance between them will prove useful during the upcoming Centennial, a gathering that Lightlark’s rulers participate in once every 100 years with the aim of breaking the curses on the six realms. Secretly, Grim has no intention of attending the Centennial, and he believes that Isla will have to die to break the curse that prevents him from wielding Cronan’s sword.

Over the following months, Isla and Grim grow closer as they seek out information about the sword. Although they both try to keep up the pretense that they are enemies and rival rulers, they become lovers. Grim and Isla discover that the blade is hidden in the Caves of Irida, which are guarded by a dragon and a series of traps. After several failed attempts, Isla nearly succeeds in claiming the sword. However, Grim chooses to protect her from the dragon even though this means they won’t be able to obtain the sword. Isla challenges his decision, reminding him that he’d sworn he was willing to sacrifice anything for his realm. Grim retorts that she’s more important, and she confesses her greatest secret: She’s unable to access her magical powers.

Eventually, Isla retrieves Cronan’s sword without Grim and demands to know the full details of his plan. He admits that breaking the curse on the weapon would kill her, and she tells him that she never wants to see him again. Weeks later, Grim senses that the final battle with the dreks is near. He tells Isla goodbye and takes her starstick to keep her from following him into danger. When Isla comes to the battlefield anyway, Grim realizes the true depths of his feelings for her. Isla saves Grim by unleashing all of her dormant powers, destroying all of the dreks but sacrificing her life in the process. Grim revives her by binding his soul to hers. Although tradition forbids Nightshade’s rulers from marrying, Grim and Isla wed and promise to love one another for all time.

The second novella is told from Oro’s point of view. As the second son of Lightlark’s king and queen, Oro is not expected to rule. However, he possesses tremendous magical power as well as a unique ability that allows him to know whether someone is lying. As a child, Oro accidentally turns an attendant into a golden statue, an accident that fills him with guilt and self-loathing. Oro’s parents send him away from home to hone his powers. His best friend, a fellow Sunling named Enya, undergoes this training with him. He also befriends a Moonling named Calder and a Skyling named Zed on his adventures.

During the war between Lightlark and Nightshade, Grim’s father kills both of Oro’s parents before surrendering. As a result, Oro’s older brother, Egan, takes the throne. Although Oro was never close to his father, he is devastated by his mother’s death. He yearns to take his grief and rage out on Grim, who becomes the Sunlings’ prisoner of war to seal the peace treaty between Lightlark and Nightshade.

One day, a child becomes lost in a forest full of monsters, and Oro enlists Grim’s help in rescuing her. Impressed by Grim’s character, Oro releases him from his imprisonment, and they become tentative friends.

About 20 years later, Oro discovers that his brother, Egan, is having an affair with Violet, the Wildling ruler, even though he is engaged to Aurora, the Starling ruler and Violet’s best friend. When Oro confronts his brother, Egan decides to call off his engagement and give the crown to Oro. Although Oro never wanted to rule, he tells Grim about his brother’s plan, and they agree to both become rulers so that they can foster peace between their peoples.

The following morning, Aurora casts deadly curses on all of the realms, but Oro believes that Grim is to blame. He allows Grim to escape back to Nightshade but promises future vengeance. Egan dies by suicide as part of a ritual to reveal a prophecy about how to break the curses, forcing Oro to become king of Lightlark.

Five centuries later, Oro invites the other rulers, including Grim, to the Centennial. The prophecy suggests that they can only break the curses if a ruler dies, and Oro believes that a powerful object known as the heart of Lightlark is key to their success.

The circumstances around Egan’s death convince Oro that falling in love would be a betrayal of his responsibilities as king, but he finds himself drawn to Isla, the new Wildling ruler. Over the course of the Centennial, he shifts from seeing her as a deceitful distraction to a potential ally. Together, they search for the heart of Lightlark. Oro gradually realizes that he’s in love with Isla, but he tries to hide this by behaving coldly towards her. He believes that she loves Grim instead.

Eventually, Oro and Isla find the heart of Lightlark. Celeste, the Starling ruler and Isla’s best friend, reveals that she’s actually Aurora, the woman who first cast the curses. Aurora also reveals that she was secretly working with Grim. For their plan to work, Oro needed to fall in love with Isla, so Grim removed all of her memories of the romantic relationship he and Isla shared before the Centennial. Aurora betrays Grim and tries to seize the heart’s power for herself, but Isla kills her and breaks the curses. Isla realizes that she’s in love with Oro. With the crisis of the curses behind them, Oro and Isla dream of creating a better world together.