Meg is an undercover security agent in her twenties who works at a Los Angeles casino. She struggles with an escalating, unacknowledged addiction to oxycodone and alcohol, which she uses to cope with her traumatic childhood. Resourceful, intelligent, and emotionally guarded, Meg checks herself into a luxury rehabilitation center as a patient to investigate the recent, highly publicized death of her sister.

Cara is the manager of the luxury rehab facility known as the Clinic. She recently accepted the position after a highly publicized scandal at her previous hotel management job left her professionally and personally damaged. Though she occasionally projects insecurity around the medical staff, Cara possesses excellent observational skills and begins to independently question the official narratives surrounding the facility's operations.

Haley is a famous country singer and Meg's sister. Educated at a Los Angeles stage school and raised in Hollywood, she possesses a heavily crafted public persona that contrasts sharply with her private reality. Her apparent death by overdose at the luxury rehab facility serves as the primary catalyst for the police investigation and Meg's undercover admission.

Max is the charismatic, aristocratic English psychologist at the Clinic. He is deeply invested in uncovering the root causes of addiction through intense trauma processing and specialized therapies. He frequently collaborates with Cara, developing a close personal dynamic with her while managing the complex psychological needs of his high-profile celebrity patients.

Dr. Lutz is the founder and clinical manager of the luxury rehab facility. Presenting himself as an aging hipster with woven bracelets and a casual demeanor, he converted a former prison into the heavily secured Clinic. His reluctance to cooperate fully with the police investigation immediately raises suspicions regarding his medical methods and the facility's financial practices.

Harry is a former New York City police officer who currently works alongside Meg in casino security. He is Meg's ex-boyfriend and remains deeply concerned about her escalating substance use and emotional isolation. He uses his law enforcement connections to run background checks and help Meg gather information from afar.

Captain Hanson is a police officer leading the investigation into the fatality at the Clinic. He is openly skeptical of the facility's official narrative and frequently clashes with the medical staff over access to records and the premises. He applies consistent pressure on Cara to stop blindly defending the clinic's founder.

Sierra is a young, famous pop star receiving treatment at the luxury facility. She is marked by a frantic, nervous energy and was the patient who initially discovered Haley's body. She struggles with intense intrusive thoughts and relies heavily on the clinic's therapeutic methods to process her anxiety.

Madeline is a former supermodel receiving treatment at the Clinic. She is an intimidating presence among the patients and is highly protective of her space and routines. She interacts aggressively with newcomers and carefully guards her connections to the facility's management.

Dex is the famous frontman of an infamous rock band, currently undergoing rehab at the Clinic to process severe childhood trauma. He is impulsive, emotionally volatile, and harbors deep, unresolved feelings regarding Haley's time at the facility.

Tom is a male patient at the Clinic who frequently clashes with others in the group. He has a history of domestic abuse and displays an aggressive, combative demeanor during therapy sessions. He openly antagonizes the other residents and creates a hostile environment in the shared spaces.

Officer Meyers is a police officer assisting Captain Hanson with the investigation at the Clinic. She helps analyze the facility's operations, runs background checks on the staff, and provides a perceptive secondary perspective on the case's oddities.

Sol is Meg's boss at Luckie's Casino in Los Angeles. He recognizes her exceptional talent for reading people but grows increasingly frustrated by her reliance on alcohol. He actively encourages her to seek professional therapy to process her past trauma.

Matthew Priest is a man from Meg and Haley's childhood who frequently appears in Meg's nightmares. His past connection to the sisters remains a dark, repressed memory that Meg struggles to uncover during her intensive detox and therapy sessions at the Clinic.