It's been a year since the clowns went on a killing spree. Everybody just thought it was the stress of the job that made them do it, but the police made a grisly discovery when performing an autopsy on one of the deceased. Genetically altered DNA spliced with rat hormones! Someone purposefully poisoned these clowns to turn them into murderous monsters. All the clues led to a reclusive scientist call Doctor X. Doctor X once respected and honored for his research into animal cosmetic surgery, but this all went wrong when a mysterious explosion took the life of his favorite test subject "Chappy". Doctor X became more and more insane, leaving society behind to work on secret experiments in unknown locations. Intelligence gathered shows that his is not only responsible for the last clown rampage; he is also launching a new attack in the back streets. It is your job to clear the streets of crazed clowns so the citizens will be safe.