Harry Poole, an introverted young man, suffers from bipolar disorder. He enrolls in a clinical trial run by the famous Dr. Lanyon, whose miracle drug is destined to help people like him lead a more balanced life. Under constant video surveillance, Harry quickly experiences positive results and turns into a new man, more charismatic and charming. He even manages to seduce Anna, a young nurse who looks after him. Harry, fully embracing his rebirth, creates a new personality for himself. "Edward Grey" is born, the man he has always wanted to be: outgoing, bold and fearless. Unfortunately, the doctor abruptly discontinues the clinical trial. Cases of rage and confusion have been reported among other test subjects and the medication is pulled. Anna, taking pity, gives Harry a parting gift: a large supply of the pills, with which he continues his own "trial" at home. Intoxicated by the freedom and power of his new identity as "Edward", Harry slowly surrenders himself to his dark alter ego and the battle for his soul begins.