The following version of this book was used to create the guide: Aster, Alex. Lightlark. Harry N. Abrams, 2022.

Lightlark takes place in a high-fantasy world where the population is divided into six realms, each connected to a different elemental force. The narrative follows the rulers of one of these realms, Isla Crown. She rules Wildling, one of six elemental realms which rely on the wildness of nature. However, due to her lack of powers because of the effect of a 500-year curse which has afflicted the whole world, her realm is slowly dying. Her only hope is to lift the curse by winning the Centennial, a once-in-a-100-year opportunity where each realm’s leader can attempt to reverse the curse. Although in theory, they could all cooperate, in order for the curse to end, in order for the curse to end one of them needs to die. Because of this, Isla has received marshall training her entire life so she can defend herself powerless self against the other rulers.

When she arrives, she meets the other six rulers and begins participating in various competitions. These competitions take place for the first 25 days of the 100-day Centennial. Whoever wins the most will get to choose who partners off with who for the rest of the Centennial. This is very important because you cannot kill your own partner. It is also revealed that before even arriving in Lightlark, Isla had made an alliance with Celeste, the ruler of the Starling realm because she had teleported to her realm using a magical item called a starstick. Their original plan is to perform poorly in all of the demonstrations so they will be paired together and will not be seen as a threat by other realm leaders. They are also trying to find the bondbreaker, a device that can take a curse away from anyone who uses it. Their plan is to use the bondbreaker on themselves in order to strip away their curse and by extension their realms’ curses. They believe this device will be in one of the realm’s libraries but fail to find it. They are also surprised to find that Oro chooses to pair himself up with Isla.

It is revealed that Oro has developed a theory about how to break the curses. He explains that Lightlark gains its life force from a magical entity called the heart of Lightlark, which blooms out of a particular type of plant on the island. Oro selected Isla because she is a Wildling and thus has knowledge of plant life. While they start searching across various corners of Lightlark for the heart, Isla also starts spending more time with Grim. Throughout the book, they grow closer after he saves her multiple times and she becomes romantically infatuated with his morally gray character and sly charm. As Oro and Isla spend time together they also become closer and bond over their mutual obligation to their respective realms.

Eventually, Oro and Isla find the heart and will be able to use it to undo the curse. However, Oro tells Isla that in order for it to be undone she must kill Grim. She cannot bring herself to do this and tells Grim. Before they run away back to his home realm of Nightshade, he reveals that they had actually met before but he had erased her memories in order to manipulate her. Devastated, she runs away and finds Celeste, who finally managed to find the bondbreaker, which they use together. However, Celeste had actually been deceiving Isla the whole time. She was actually a disguised Aurora, the original leader of the Starling realm when the curse was cast and the original caster of the curse. Aurora is about to kill Grim, Oro, and Isla before conquering Lightlark but Isla is able to defeat her. Isla almost dies after the battle but Oro saves her, showing that he was the one for her. After the book’s conclusion, Oro and Isla move into his castle together.