A guy is walking past a high, solid wooden fence at the insane asylum and he hears all the residents inside chanting, "Thirteen! Thirteen! Thirteen!" He continues walking along the long fence, but, being a curious person, he can't help but wonder why they are chanting "Thirteen!" over and over. Could it be that they are chugging beer? Are they perhaps taking turns beating one of the inmates? Maybe they are counting the number of patients that have leapt off of the roof thus far.