New York's star medical examiner, Dr Henry Morgan, doesn't study the dead only to help solve criminal cases. Born 200 years ago, he hopes his work also will help solve mysteries about his own mysterious immortality. The remarkable observational skills he has developed over his long life impress his new partner, Detective Jo Martinez, and as they get to know each other, more of his colourful past slowly reveals itself - even as he continues to keep his long life secret from everyone except his best friend and confidant, Abe.