In one episode, American Horror Story: Coven (“season 3”, in typical television vernacular) has established a keener focus than was seen in the whole stretch of last year’s Asylum. That’s an achievement in and of itself; Asylum, unlike the series’ premiere installment, Murder House, went all over the place and brought the kitchen sink back with it. Aliens, Nazis, the devil, killer Santa clause, evil children, an Ed Gein-alike, Anne Frank (yes, Anne Frank), and all the joys of a clergy-backed nuthouse gave Asylum the sensation of weightless indecision. On first impression, the witchcentric Coven won’t have that problem in the slightest, though there’s always room for clutter. For now, we can all rest…