You know this much about Marc Jacobs: You never know what he'll do next. Replacing the Nittany Lions marching band and his spring parade of high-school good girls gone bad were Philip Glass' symphony Heroes and a troupe of vagabonds in muted layers of plaid flannel, oversize knits, skirts worn atop pants, legwarmers, and tams whose cumulative effect was paradoxically chic.

When pressed for details backstage, Jacobs was vague. "It's about the places I've been, the people I know, world leaders, and winter," he said. The one word he didn't use, though it was uttered by many in the audience, was grunge. Was this a reprise of the seminal collection that lost him his job at Perry Ellis back in 1992? Jacobs wasn't saying. But you saw elements of it in the flannel that was repurposed as strapless dresses, the sweaters that dragged along the knees, and the pants that were so puffy they looked as though they required their own hand pump. (Somewhere, Kal Ruttenstein, the man who famously championed that controversial collection and to whom Jacobs dedicated this show, was smiling.) Come evening, the designer's gorgeous urchins wore black net and metallic sequin dresses distressed to the point of tatters. In the midst of all this were eminently functional, not to mention desirable, coats, capes, shawls, and jackets. And, of course, superluxe bags; this wouldn't be a Jacobs runway without them.

Jacobs is making a habit of 180-degree reversals—gloomy one season, polished and upbeat the next, and now, for fall, disheveled once again. It's remarkable how a man who claimed post-show that he "didn't know what to do" can be full of such captivating ideas.