the big shift; After seasons of feminine frills, fall marks the return of the tunic-boxy, clean, strong, and perfect for work.

Byline: Sarah Mower

Exactly four looks into the YSL fall show, my epiphany happened. It was a tunic, a gray double-face-cashmere tunic, furiously modeled-hands jammed in pockets, bangs in eyes-by Irina Lazareanu, that Canadian/Romanian rock chick with the Patti Smith/Chrissie Hynde thing going on. In the two seconds it took to read her outfit-high neck, long sleeves, belt, narrow pants, platform boots-the mild fashion depression under which I'd been languishing for ages suddenly lifted. I can name it now. This is the low-grade misery of a boyish, minimalist, straight-up-and-down, covered-up trouser person trapped in a five-year cycle of ladylike, frilly, curvy, revealing dresses. When fashion turns against your physical type, I can tell you, you've had it. There's nothing to do except smile brightly (since resenting fashion is never a good look), strive to cobble together a daily compromise, keep faith, and know this: One day, something else will come along. You won't be able to predict how or when, but you're going to know it when you see it.

And now it's here, all thanks to YSL's Stefano Pilati, who so concisely nailed an important piece of newness in that gray top and its matching pants. "To tell you the truth, it's my favorite thing in the collection," he tells me. "I'd been thinking of doing something more masculine. And versatile. You can wear this tunic over pants or a straight skirt, or use it as a dress. I like that flexibility." I can list what's exciting about this specifically Saint Laurent prescription for getting dressed: It's for day; it's formal and grown-up while also being cool and ever-so-slightly unpredictable. The tunic is smooth and matte and understated, but there's something in the box-pleated volume of the sleeves that is edgy, intriguing, almost Cubist. I like being caught off guard by it, too. For ages I'd been drumming my nails waiting for a definitive trouser suit, a tailored jacket and pants, to come along to save us. Wrong! That was a nineties solution. Having the tunic turn up as a different answer to the same old problem is the sort of creative push we need to feel we're living in the present. Pilati is not a nineties designer.

He kindly lent me the look to test-drive, because there are some things you can't appreciate about new clothes until you get them on, stare at yourself in the mirror, move around. In this case, it's the proportions, which magically stretch you out to your maximum potential. Starting from the top, it's in the relationship between the fullness of the sleeve and the length of the tunic; it's about the point where the hem hits the top of the thigh, the width of the pant, the crop of the leg. That optical effect, already narrowing and elongating, gets yet more exaggerated when you step into those great slick platform boots. Suddenly there's this slimmer, taller, more Amazonian person looking ...