Subject: CHUPACABRAS Location: USA. Animal X travels to Puerto Rico to investigate the Chupacabra - a creature that sucks its victims dry of blood. There we speak with eyewitnesses who have encountered this terrifying beast. Subject: ESSEX PANTHER Location: UK. In Essex, England we meet residents who have had their country invaded by wild black panthers. Where did these Alien Big Cats come from and how dangerous are they? If one Big Cat expert is correct England is in for a serious problem. Subject: PET DETECTIVES Location: USA. We look at the extraordinary tale about one of man's most fatal diseases and the dogs that can diagnose it. They are our companions, our protection and often one of our best friends. But are dogs about to become the guardians of our heath as well?