In this last episode Professor Hood (Patrick Stewart) sets out to discredit a doctor's claims that one of her patients has been cured of cancer by drinking ordinary spring water, convinced she's perpetrating a cynical hoax. To his surprise, she seems every bit as baffled and sceptical as him, and readily offers to help investigate the case. Unfortunately, just as an explanation seems within reach, she is found dead, having apparently committed suicide. (thetvdb.com)