A psychiatrist is tormented by a man calling himself Cerberus. Cerberus claims he was rejected for treatment and is determined to take revenge by extorting the psychiatrist. Cerberus, to show he means business, begins harassing the psychiatrist's patients, including a young man dying of a brain tumor and a suicidal woman. McGarrett & the Five-O must deal with this cunning and ruthless adversary.
—Bill Koenig