The formerly tranquil city-state of Lisvalletta is now plagued by a perilous new drug known as Anthem. The drug's side effects enable users to enter an Overdrive state, mutating them into superpowered beasts possessing inhuman abilities. With the police unable to halt this emerging threat, the duty falls to the Special Crime Investigation Unit SEVEN-O. To mitigate the risks of this work, investigators operate under the patented "Double Decker" system, which mandates that they partner up in "buddy cop" pairs. As a child, ordinary police officer Kirill Vrubel dreamed of being a hero who would rescue his school from a random terrorist attack. His opportunity to become a hero arises when his landlady blackmails him into finding her lost cat. After arriving at an abandoned warehouse and falling asleep, Kirill finds himself in the midst of a hostage situation involving an Anthem user. By teaming up with SEVEN-O detective Douglas "Doug" Bilingam, Kirill secures his place as the newest member of SEVEN-O. Now, with the assistance of this secret organization, he may finally realize his dream of becoming a hero.