Iris Van Herpen has taken her haute couture R&D to another astonishing frontier, creating a “living look” incorporating 125 million bioluminescent algae that she said require eight hours of rest, eight hours of light — and a calm, cool environment in order to thrive.

Sounds a lot like us, huh?

“When it’s happy, it responds to the movement of the person who’s wearing it,” Van Herpen told a visitor, his jaw on the floor, during a preview of her fall 2025 show, which combined light sculptures, stirring music, gossamer fabrics and choreography to pack an emotional punch akin to David Attenborough’s new ocean film — but with the visual poetry unique to the Dutch designer.

A million questions occur about the algae dress, such as, “How long will it live?”

“We don’t know. No one knows. It’s one big pioneering process,” Van Herpen said. “But I don’t think this will be possible to deliver to a client yet. It’s more of a museum piece because it really needs to be taken care of every day.”

Van Herpen fished out a photo on her phone of the squishy garment housed in its steel and glass temperature-controlled chamber, mist accumulating at the bottom. It’s as strangely beautiful as it is mysterious, achieved thanks to a collaboration with engineer and “bio designer” Chris Bellamy, who found a way to keep the algae alive in a nutrient gel.

Each of Van Herpen’s 18 looks felt like an ecosystem unto itself: here a kinetic dress in collaboration with artist Casey Curran, undulating like some alien skeleton; there Japanese “air” fabric suspended on wires and drifting like a jellyfish in invisible currents, or a cutting-edge “brewed protein” material from Spiber, somehow resembling the suckers of an octopus — or a few cans of Pringles — spilled over a fishtail dress.

The designer combined all that science with haute artistry, also taking inspiration from Loïe Fuller, a pioneer of modern dance, and equipping a performer with winged appendages that interacted with the laser beams of Nick Verstand in mesmerizing ways. Van Herpen called that show opener a metaphor for “how we have drained the life out of our oceans.”

Leaving no senses unengaged, she also conscripted perfumer Francis Kurkdjian to develop a bespoke fragrance dispersed like a wave during the show.

Here were vaporous dresses that behaved in the atmosphere of the Élysée Montmartre music hall like normal fabric might submerged in Europe’s deepest pool — Van Herpen’s been there, done that for her spring 2023 couture collection — and a stiffer one that whorled upwards around a model, like egg whites caught in a twister.

Van Herpen’s wondrous dressmaking defies gravity, provokes deep thoughts about our planet — and lights up couture week like very, very happy algae.