Fashion's obsession with the masculine/feminine thing goes back at least as far as the heydays of Yves Saint Laurent and Helmut Newton. And yet it never seems to get old—see any number of runways this season, from Michael Kors to Nina Ricci. But trust the Maison Martin Margiela team to put their own stamp on it. In the shadow of the Eiffel Tower, windows open to a gorgeous breeze, the Maison show today wasn't so much boy-meets-girl as it was boy-meets-showgirl. Paris, Nevada, let's call it. Spangled briefs peeked from the top of low-slung men's pants, and a pink sequined bustier stood out against the black of a topcoat and trousers.

By rights, this should've felt predictable. But if it wasn't agenda-setting the way Margiela the man's collections could sometimes be, it didn't fail to charm anyway. That's mostly due to the excellent cut of the Maison's tailoring—an unassailable pair of pinstripe trousers, or a clever gilet that combined structure and flou. It's hard to make a real-world case for sleeves hacked off at the shoulders and suspended from the neck by grosgrain ribbons; no one wants to work that hard at getting dressed. But lapel-less coats in leather or brushed cashmere? Despite the mad bits of sequins worn underneath, they were utterly desirable. Replica pieces apparently re-created corsets and bustiers lifted from real circuses. They razzle-dazzled you. In the end, though, the masculine side of this story edged out the feminine.

BRAND: MAISON MARTIN MARGIELA  |  MAISON MARTIN MARGIELA OFFICIAL WEBSITE

Isabel Marant is about to get the H&M treatment, following in the footsteps of labels like, most recently, Maison Martin Margiela and, going back a few more years, Stella McCartney and Karl Lagerfeld. Not bad company. Marant's new collection for the fast-fashion giant is launching in November following a big Paris bash. Maybe that's why this collection found the designer reengaging with the tough-yet-romantic trope that first started her down the road to mega-success. As she reminded us backstage, "It's the contrast of two ideas that I'm always trying to work with."

The first look out put that statement into motion, with its strong-shouldered black jacket counterpointing a not-much-longer lacy white slip of a dress. In other instances, Marant paired her frothy white tops (like designers elsewhere, she's embraced the ruffle) with black leather. Side-laced leather pants looked edgier than usual for her. But for every step she took toward the dark side, Marant took another into the light. Painterly blooms on frilly chiffon looked positively sweet. Then, again, by the end of the collection she was back into the grommets and sequins. Grommets covered the season's new shoe, a suede Mary Jane/bootie hybrid that didn't quite work. The collection's lasting impression was of a baby pink ruched and ruffled jacket paired with sexy white eyelet jeans. Sweet, but with a serious bite—that's the essence of Isabel for Spring.

BRAND: ISABEL MARANT  |  ISABEL MARANT OFFICIAL WEBSITE

Our review will be posted shortly. See the complete collection by clicking the image at left.

BRAND: SONIA RYKIEL  |  SONIA RYKIEL OFFICIAL WEBSITE

Our review will be posted shortly. See the complete collection by clicking the image at left.

BRAND: TALBOT RUNHOF  |  TALBOT RUNHOF OFFICIAL WEBSITE

The prefix trans- means, among other things, "beyond" and "changing thoroughly." There's not much more you need to know about Raf Simons' show for Christian Dior today than that this was, according to his show notes, "Trans Dior."

Of course, that's not strictly true. Whether you actually need to know it or not, you might like to know that the collection represented a startling dissection of Christian's codes, and an equally striking injection of Raf's. The bifurcated Bar jacket that launched the show was the barest statement of intent. And he's always liked badges and insignia—the emblems of clubs, gangs, tribes, youth cults—so it was fascinating to see him apply them to a clubhouse as heavily codified as Christian Dior.

Equally, Simons took his own fascination with slogans, gave it a distinctly surreal spin, and embroidered it all over dresses printed with hyper-real iterations of classic Dior flora. "Alice Garden" read one such slogan, and suddenly everything fell into place: The setting for the show, a psychedelic farrago of plant life real and fake, was the wonderland into which Alice fell. We were all down the rabbit hole. "Primrose path" read another embroidered slogan. As Raf himself wondered after his show, where might that path lead?

In this case, it most definitely ended up in a world where, like Alice, Dior had topsy-turvied. Ladylike pleats went sideways, Dior's pretty garden was toned toxic, seaweed beading crept eerily over shoulders and around throats. Even an otherwise lovely shirtdress in a light gray wool was bound in the indignity of a metallic-pink bustier. Something about that contrast between classic and crass felt like a clue to what Simons was up to: Respect for the past is all well and good, but the future won't wait (a metallic-pink bustier standing in, in this case, for fabulous things to come). He's always been urgent like that. And yet, given that Simons is not one of those couturiers who was born with a needle and thread in their hot little hands, his remarkable instinct for form and color revealed him here as a natural upholder of fashion's fundamentals: silk skirts that ballooned on the hips shouldn't have worked but did, with able assistance from startling combinations of green and ice pink, orange and lilac.

Toward the end, Vlada Roslyakova appeared in a Bar trouser suit, the classic Dior silhouette, but when she turned, the jacket's flaring hip had been sliced into a bustle of acid-floral-printed pleats. The Bar silhouette was also sprinkled through a final parade of strapless silver jacquard dresses. In another era, they'd probably have been called cocktail dresses, but they were metal, and each woman was wearing one of Raf's emblems, as if they were members of a secret society. Simons' Women? After Prada in Milan, and Rick Owens yesterday, it's fair to say that the tribes of fashion are in mighty shape.

BRAND: CHRISTIAN DIOR  |  CHRISTIAN DIOR OFFICIAL WEBSITE

Our review will be posted shortly. See the complete collection by clicking the image at left.

BRAND: ISSEY MIYAKE  |  ISSEY MIYAKE OFFICIAL WEBSITE