Sherlock Holmes is plunged into the most dangerous mystery of his career by his brother Mycroft and the British Secret Service. He is sent to Sumatra to uncover the mystery of a missing British secret agent. Mycroft, his older brother involved in foreign policy hopes to secure the Dutch Indies if there are proven oil deposits. But Holmes finds more than oil, an energy source that will change the world. Living between societies of cannibals and Dutch colonials he uncovers the terrible secret of the Giant Rat of Sumatra.