Mikey is an 18-year-old high school senior coping with the impending reality of graduation and separation from his friends. He struggles with obsessive-compulsive disorder and anxiety, which are exacerbated by his family's dysfunction. He deeply values his chosen family of friends over the supernatural events happening around town.

Jared is Mikey's oldest friend, providing crucial emotional support and physical grounding when Mikey's anxiety flares. Though he appears to be a normal high schooler, he is quarter-divine through his cat-goddess grandmother and possesses limited healing abilities. He fiercely protects his privacy and personal life.

Mel is Mikey's older sister, graduating in the same class as him after losing a year to a severe medical emergency caused by her anorexia. She possesses a mix of bold self-confidence and quiet insecurity, stepping up to defend her siblings from external threats while quietly managing her health.

Henna is a close friend to Mikey, Mel, and Jared, dealing with family pressures regarding an impending mission trip to Africa. She carries the lingering trauma of losing her older brother to a previous supernatural incursion. She is direct, open to new experiences, and prefers to address problems head-on.

Satchel is the protagonist of the supernatural narrative occurring in the background of Mikey's life. As an indie kid, she possesses an idealized home life but is constantly thrust into dangerous, world-saving quests involving otherworldly beings. She is bright, talented, and frequently caught in dramatic interpersonal entanglements while battling the Immortals.

Nathan is a recent arrival to the high school who quickly integrates into Mikey's friend group, much to Mikey's jealous chagrin. He is a former indie kid who moved to escape his past after losing his sister to vampires, giving him a shared understanding of trauma with Henna.

Mrs. Mitchell is an ambitious state politician whose sudden bid for a national congressional seat thrusts her family into the spotlight. She struggles to balance her political career with her children's needs, often appearing cold or calculating, though she harbors her own complex fears about the world.

Mr. Mitchell is the father of Mikey, Mel, and Meredith. Struggling with severe alcohol addiction and the regret of past mistakes, he is largely absent from his children's daily emotional lives. He depends on his children for support rather than providing it, modeling a fractured sense of adulthood.

Meredith is Mikey and Mel's younger sister. She relies heavily on her older siblings for guidance and protection in the face of their parents' dysfunction. She is eager to experience life, as evidenced by her determination to see her favorite band despite restrictions.

Finn is an indie kid whose sudden death in the woods sets off the latest supernatural crisis in town. He shares a name with several other indie kids who populate the background of the high school's social scene.

Dylan is an indie kid who supports Satchel through her grief. He harbors romantic feelings for her and acts as a close confidant in her world-saving circle.

The Prince is a member of the Court of the Immortals who makes contact with Satchel. He presents himself as an ally who has fallen in love with her, claiming he wishes to protect her from his family's ambitions.

Satchel's uncle is a local police officer tasked with investigating the mysterious deaths around town. He serves as Satchel's inside connection to law enforcement before becoming entangled in the supernatural invasion.

Dr. Luther is Mikey's therapist, who helps him manage his recurring obsessive-compulsive behaviors and anxiety. He provides a grounded adult perspective, helping Mikey realize that his mental health struggles require professional tools and patience.

Steve is a young, capable doctor who treats the teens after a deer collision. He quickly forms a romantic connection with Mel, offering her a steady relationship during the town's chaos.

Mr. Shurin is Jared's father and an underdog political candidate running against Mrs. Mitchell. He is a supportive father who offers his lake cabin for the teens' post-prom party.

Jared's grandmother is a supernatural being who fell in love with a mortal man and remained in the human world. Her divine lineage provides Jared with his limited healing abilities.

Kerouac is an indie kid whose actions inadvertently allow the Royal Family of Immortals to enter the human world. Before his demise, he leaves a crucial protective amulet for Satchel.

The Empress is the leader of the Immortals, a supernatural race attempting to cross over into the human world to feed on its life force. She requires a human vessel to permanently inhabit the mortal world.