Twenty-five years ago, Peter Jensen became obsessed with Reversal of Fortune, the movie that won Jeremy Irons an Oscar for playing Claus von Bülow, accused and acquitted twice of trying to murder his socialite wife, Sunny, by overdosing her with insulin. Does anything about that scenario suggest the genesis of a fashion collection to you? The fact that it did to Jensen—even more so, the fact that he nursed his peculiar passion for a quarter of a century before allowing it to feverishly flower throughout his latest collections (Pre-Fall for women, Fall for men)—is one key reason why he endures as one of London's most diverting fashion cults.

The unlikeliness of the comatose Sunny von Bülow (it took her 29 years to finally expire) as a muse was counteracted by Jensen's astute mining of her aristocratic WASP lifestyle for Pre-Fall's inspiration: knitwear patterned after the carpets of a grand family estate in Rhode Island; a print based on the deer that would have roamed said estate; prim, box-pleated wool dresses lined in habotai silk; capri pants paired with striped cotton shirts. There on his mood board was Sunny with her signature helmet of lacquered hair, alongside a photo of the equally soignée Carmen dell'Orefice in a camel duffel coat. So far, so elegantly straight.

But Jensen doesn't do straight. Among Sunny's many weaknesses was an addiction to M&M's. Jensen encrusted his shoes with a monochrome version. A classic camel cardigan was reconfigured as a bed jacket with a varsity letter (just the trick for putting a bedridden American aristocrat in touch with her roots). Jensen said he was thinking of the Von Bülows' party lifestyle when he created a print out of diamond studs. In the anagram design he made of the randomly distributed letters in his and Sunny's names, what ironically stood out was a big RSVP. The designer insisted it was mere coincidence, but he couldn't deny that it kind of matched the droll, decadent undertow of the collection.