A killer parasite is on the verge of threatening 180 million people… and a race against the clock has begun! What do two Japanese detectives, a naked man on a city street, and a roundworm from Botswana all have in common? Ken Mizoguchi and Nao Inoue are a pair of investigators asking themselves this very question as they string together clues to solve a string of bloody and mysterious murders. But as the pieces come together, they begin to uncover the threat of a deadly biological agent which poses a threat of epidemic proportions. An unlikely lead sets them off on the hunt for a mysterious photographer, but as they chase down shadows, the infection keeps spreading.