In a squalid, DNA-stained alley behind the club, Ethan Kath and Alice Glass of Toronto's Crystal Castles are injecting their goth-muse voodoo droid with probiotic sugar water. The muse was flatlining. The sugar water is complex, produced in a costly chem lab—it hits the droid's bloodstream like crushed-up Adderall SweeTarts coated in a cocaine-codeine combo. The droid snaps to and sits up with wide eyes, looking like a character from Edward Gorey's The Gashlycrumb Tinies. It opens its latex speaker-mouth, and the song "Transgender" comes out, from Crystal Castles' third full-length, III. Mutated, metallic ping sounds float over an ominous Gregorian synth-bass bed. Glass's distant vocals are basically unintelligible, "Will you ever preserve, will you ever exhume?" It has that post-rave/empty-cathedral feel. Beats shake and sift their way in; a kick lands and steers it into an improbable requiem banger. Death-march EDM. To record III, the duo isolated themselves with a 1950s-era tape machine in Warsaw, Poland. Themes on the album center on oppression. Images of blood mix with melancholy and chemicals in the dirt. When they flatline, their sugar water revives them. Kath and Glass spoke.

The lyrics for "Transgender" seem lost, yet leading—pained and headstrong. Where do your words come from?

Glass: Where does anything come from? As a lyricist, I like what bands like Crass and Crisis did, politically. They wanted to inform the masses of injustice in the modern world. Take human trafficking, for instance—America isn't doing enough to fight human trafficking within its borders, and something like 50,000 women are trafficked into America every year. There aren't enough shelters for victims, and many victims are placed in juvenile treatment facilities. Statistically, one in 12 children in America will be sexually assaulted. The biggest threat to women's safety and health is domestic abuse, but there is little funding to educate and help women. Stuff like that needs to be brought to light.

In "Affection," you say you catch a moth in your hand and crush it casually. How do you crush a moth casually?

Glass: You tell me.

Moths get such a bad rap. Everyone's always scared of them. Just because they're gray? And have to eat your old T-shirts to live? While butterflies get all the bright colors? How come no one's afraid of butterflies?

Glass: That's a great question, but not what the song's about.

What are some of your favorite reads and writers?

Glass: Albert Camus, Sylvia Plath, Louis-Ferdinand Céline's Journey to the End of the Night.

Why did you choose to record the album in Warsaw? How was it?

Kath: We chose Warsaw because we didn't speak the language and we didn't know anyone there. We wanted the isolation. We like the cold weather, too [laughs]. We tried to keep the takes to a minimum, to keep it more live, with no editing. The first take usually captures a more raw expression of emotion, and nothing is corrected. We left wrong notes in there. When stuff gets corrected and edited, the song loses itself a bit. We didn't want that.

And no computers were allowed?

Kath: Right. We banned computers from the studio and living quarters, and we used 1950s tape machines to track everything.

Your shows are unpredictable. Alice is unhinged. What are your thoughts on live shows versus the album?

Kath: Shows and albums are two completely different entities. When recording, we're capturing something—an idea or sound, something melancholy. The live show is more about power. Alice can be an animal out there. The first time I saw her performing, she was in a punk band called Fetus Fatale. These sexist older guys who had been in big local punk bands in the '80s were shouting at her to get off the stage and that girls shouldn't play punk. She started spitting beer in their faces and yelling back at them, telling them that they were wimps. She was smaller, a teenager, sticking up for herself and spitting on these legends, while shouting what I thought was this beautiful poetry.

I was checking out the Crystal Castles forums, and there were two girls arguing about eye makeup. It was brutal: all this stuff about primers and eye shadows, one of the girls called the other one a "cow." If I had to put that stuff on, I'd poke my eye out. I'm sure you're on the forums all the time, right?

Kath: Not so much [laughs]. I've been asked about the forums before. We try not to look at the internet. We try to pretend it's 1990. We have a guy who checks our e-mail.

What do you associate your music with? Is it sound, or emotion? Or just moths?

Kath: I think our music is bleak, maybe lonesome, and sad. I think those are the biggest emotions we have when we write.

I'm going to find an empty cathedral after this, and I'm going to crank Crystal Castles in there while I save all the moths with my Edward Gorey droid.

Kath: I like that. Don't poke your eye out.