Dr. Henry Morgan is a charismatic New York City medical examiner who possesses a profound secret: he is immortal. Having lived for over 200 years, every death he experiences results in him mysteriously vanishing and reappearing naked in a body of water, completely reset and ageless. Alongside his loyal antique-dealer friend and confidant, Abe, Henry uses his vast medical knowledge and centuries of life experience to help NYPD detective Jo Martinez solve complex murder cases. While working in the city morgue, Henry tries to conceal his true identity while desperately searching for a cure or an explanation for his condition. His existence is further complicated when he begins receiving cryptic phone calls from another immortal, a man known only as Adam, who has grown weary of living after millennia of experiencing the same curse. As Henry and Jo form a deep professional and personal bond, Henry must balance solving high-stakes homicides with keeping his extraordinary past a tightly guarded secret.