Black Box follows the life of Catherine Black, a world-renowned neuroscientist who hides a dark secret: she suffers from bipolar disorder. While she is a brilliant doctor at the Center for Neurological Research and Treatment in New York, she struggles to manage her own mental health, often going off her medication to maintain her creative edge, which leads to erratic and dangerous behavior. As Catherine treats patients with complex neurological conditions, she must navigate the delicate balance between her professional brilliance and her personal instability. The series explores the intersection of medical mystery and psychological drama, as Catherine's colleagues and family begin to suspect the truth about her condition, forcing her to confront the possibility that her own mind might be her greatest adversary.