The year is 1999 and Tokyo's Mobile Police have a new weapon in the war on crime--advanced robots called Labors are used to combat the criminals who would use the new technology for illegal means. The suicide of a mysterious man on the massive Babylon Project construction site sets off a cascade of events that may signal the destruction of Tokyo. What is the connection between the suicide, the new mobile Police AV-XO Zero Labor, and a berserk prototype tank? When Patlabor cops Noa Izumi and Azuma Shinohara investigate an unexplained wave of rogue Labors rampaging across the city, they uncover a sinister revenge plot to infect Tokyo's population of 8,000 Labors with the deadly BABEL virus.