If his audience was bemused by the distinctly un-Erdem-like collection he presented today, Mr. Moralioglu himself was way ahead of them. "It's a departure," he declared before the show. "Leaving certain things out felt like freedom." So, with clean slates on his mind, Erdem looked to that ineffably English institution the public school for inspiration. But it wasn't so much posh rugger buggers storming around in a pubertal stew of hormones that he drew on to shape the nature of his new collection. Thank heavens for that small mercy. Rather, it was, as he put it, "rebels and jocks and nerds and boys who put their mothers' couture dresses over their school shirts." More Sebastian Flyte, in other words. Which explained at least one recurring theme in the show: the crisp cotton shirtdresses veiled in swaths of tulle.

Cross-dressing teens don't immediately present themselves as an obvious wellspring for a designer who has dressed the wives of presidents and prime ministers. But Erdem has always been an intensely strange one. If the schoolboy (or girl-dressed-like-schoolboy) subtext insinuated itself in very subliminal suggestions of a sweatshirt, a rugby shirt (there were stripes), or gym kit, what came across much more strongly—or perhaps "ethereally" is a more accurate descriptive—was a deep, plangent melancholy, helped along by the cellist and pianist who played center stage.

True, the teenage years are a time of irrational highs and lows, and the organza shell tops that Erdem covered with scrawled poems by Emily Dickinson and Walt Whitman certainly reflected that emotional roller coaster, but it was actually adult rituals like weddings and funerals that seemed more true to the monochrome mood of his presentation. In fact, front-row fan Alexa Chung said she felt like she'd seen clothes that offered the opportunity to dress as a bride and a widow in the same outfit. "The two sides of my brain," Erdem responded when he heard that. But even before the androgynous girl/boy school inspiration struck him, he insisted, the blankness of the white toiles in his studio had gripped his imagination. "Something ghosty," he said. "The woman is a shadow."

And that is why, for all the obvious effort and the couture-worthy workmanship, this Erdem collection ultimately felt insubstantial, and overwhelmed by sadness.