Some designers have more bark than bite. But with their dramatic Fall collection, Kate and Laura Mulleavy proved they have plenty of teeth. And sharp ones.

It was, said Kate, "a continuation of something that started last season." Japan was again the starting point of the sisters' journey, but the happy, shiny, pastel-colored, and manga-inflected confections of Spring gave way to "slasher" dresses in black, white, and bloodred. The Mulleavys turned their imaginations loose on "the connection between the Kabuki tradition and that of modern Japanese horror films." Yes, the gothic knitwear had a torn-web quality, and the torturous, sadomachistic shoes (a reworking of last season's) wrung winces from the audience, but the show was bigger than just that, more ambitious. String sculptures by the German-American artist Eva Hesse gave birth to the shaggy pieces with a primitive rag-doll look. Romantic, full-skirted cocktail numbers looked like they could have been painted by the Impressionist Edgar Degas.

The sisters—who have a successful Gap collaboration under their belt—are gradually increasing the percentage of daywear in their collections. For Fall there were tailored coats and zip-pocket pants and even (sheer and lustrous) oxford blouses. This is a smart move, not just because it will broaden their retail reach, but because occasions to wear wispy party dresses don't come along every day. But then again, neither does the Mulleavys' extraordinary talent.