A devoted husband, proud father of four children in their 20s, and respected police officer, Joe O'Brien begins experiencing bouts of disorganized thinking, uncharacteristic temper outbursts, and strange, involuntary movements. He initially attributes these episodes to the stress of his job, but as these symptoms worsen, he agrees to see a neurologist and is handed a diagnosis that will change his and his family’s lives forever: Huntington’s disease.