The artists Allyson Mitchell and Deirdre Logue were in Philadelphia last week, at the Icebox Project Space, staring up at the “Non Binary Goddexx”: an eighteen-foot inflatable Tyvek sculpture with one massive breast, a hairy nipple, a slight mustache, and inconclusive genitals that, at regular intervals, released a gush of “fluid fluid” into a bucket. Mitchell looked concerned: “They’re not spewing enough!”

“We may need to top her up,” Logue said. She smirked, and clarified, “The Goddexx goes by ‘she’ or ‘they.’ ” The ambiguously gendered giant is one of dozens of pieces that Logue and Mitchell created for the latest iteration of Killjoy’s Kastle, their breathtakingly elaborate, impressively deranged, and surprisingly popular lesbian-feminist haunted house.

More than five thousand people saw the version they erected in West Hollywood in 2015; every night, a line of eager hipsters waited for the chance to be led through the spectacle—past the cave of the “Polyamorous Vampiric Grannies,” through the “Riot Ghoul Dance Party”—by one of the “demented women’s-studies professors” who serve as guides. (In Mitchell’s new book about the project, this character is described as “precariously employed, hairy lipped, overcaring and oversharing, and she sweats in her perimenopausal silk shirt, angry, outdated.”) Like the TERFs—trans-exclusionary radical feminists—who are condemned to spend eternity mopping up the Goddexx’s excretions, “the dementeds,” as Mitchell and Logue have nicknamed the guides, are undead: all the characters in Killjoy’s Kastle hover in an eerie afterlife, a perverted purgatory of women.

Logue and Mitchell were inspired to make the first Kastle in their native Toronto, in 2013, after seeing a documentary about evangelical Christian Hell houses: fearsome enactments of the punishments that will supposedly befall sinners who engage in homosexuality, suicide, abortion, and so on, which parishioners spend months developing, in order to scare the public straight. “We were really blown away by how a community comes together to articulate an ideology through visual art and performance,” said Mitchell, who has long silver hair and was wearing purple jeans and burgundy sneakers. “We started wondering, What would a lesbian-feminist back-to-school-themed window display look like at Staples? What would a lesbian-feminist Santa Claus parade be?”

A haunted house would give them the chance to manifest the culture’s most frightful ideas about lesbians and feminists—that they’re killjoys or “happiness murderesses”—with humor and wild abandon. Killjoy’s Kastle in L.A. featured the forge of the “Ball Bustas”: a pair of tough dykes whose perpetual task was smashing plaster casts of “truck nuts”—the ornamental rubber testicles that people hang from the backs of their vehicles—with hammers, in an endless simulation of busting up the patriarchy. “We loved it,” Mitchell said with a sigh. But there is no nut-bashing in Philadelphia, owing to complaints about “trans misogyny.” Mitchell shrugged.“We have creative minds; we’re flexible,” she said.

Next, they stood in front of the “Graveyard of Dead Lesbian Feminist Ideas and Organizations,” a group of surprisingly realistic Styrofoam headstones for bygone institutions like the Michigan Womyn’s Music Festival, the gay gene, and the Lexington Club (a now defunct San Francisco bar), all perched on a lazy Susan. “We’ve made fifty-seven new graves just since we’ve been here!” Logue said. They went to Philadelphia in August, and have been working on the Kastle ever since. Mitchell said, “We miss our cats.”

Logue and Mitchell met twenty-five years ago. “It was love at first sight,” they said in unison—though another decade went by before they became a couple, and then a few more years passed before they started working together. “I swore I’d never collaborate with a lover,” Mitchell said. “But then we had a conversation where we decided that we were just going to be all-in—and there would be no separation between our home, our studio, our practice.” They opened FAG—Feminist Art Gallery—at their house, in the Parkdale neighborhood, in 2010. “We said we would only have four shows in the first year,” she continued. “We had something like thirty.”

Even with grants from the Pew Center for Arts & Heritage and the Canada Council for the Arts, both women have day jobs: Logue works for a video-arts-distribution organization, and Mitchell is a “real-life demented women’s-studies professor.” The previous evening, she had filled in as a tour guide. “We always ask our dementeds to come up with a character, but I hadn’t had time,” Mitchell said. “Then I was, like, Wait a minute. I run one of the largest graduate programs in gender, feminist, and women’s studies in North America: I don’t gotta make shit up! I’m fucking me.”

A line was forming by the door. There were only a few nights left: they dismantle the Kastle just before Halloween. “The ultimate killjoy,” Logue said with pride. ♦

An earlier version of this article misidentified the source of a grant.