The cover of Ulver’s album Flowers of Evil. Credit: Courtesy the Artist

Norway’s Ulver debuted in 1993 as a howling black-metal outfit, but since then front man and composer Kristoffer Rygg has steered his ship into such different waters you can hardly say it’s going a-Viking anymore. (If you want to hear Ulver at their heaviest since their early days, I’d recommend their collaborations with Sunn O))), 2003’s “Cut WoodEd” and 2014’s Terrestrials.) But almost any questions you could have about the life, times, and journey of this band should be answered in Wolves Evolve, the book companion to their new Flowers of Evil (both via House of Mythology), which is a memoir, scrapbook, and manifesto in one. Rygg is Ulver’s sole remaining founding member (though programmer and keyboardist Tore Ylwizaker joined in 1998), and he’s said he wanted to do a book for the project’s tenth anniversary, and then its 15th—so it’s thrilling that it’s finally arrived. Flowers of Evil doesn’t break radically from its predecessor, 2017’s The Assassination of Julius Caesar—it’s a dark electronic work infused with gothic atmospheres and Krautrock, and it’s heavy on the literary historical inspiration. The album title nods to Charles Baudelaire (just as some of Ulver’s early work was inspired by William Blake), and several songs, including the eerie title track, incorporate quotes and references to poetry. Ulver are a very narrative-driven band, and their lyrics—which Rygg delivers in a clean, crisp vocal style these days—are essential to grasping the themes of each album. On “Nostalgia,” haunting female vocals and a gently cantering beat build up into a snapshot of time, of memories of past lives, and of old houses that are “forever haunted.” But most of the album is about apocalyptic fears, spiritual betrayals, and the dangers of delusion. “Apocalypse 1993” is at heart about the Waco tragedy and the ease of falling into cults that invent matters of spiritual life and death out of whole cloth. The closest the album has to a true battle march is “Machine Guns and Peacock Feathers,” which locates Rygg’s end-times vision of “Michael and his angels versus the dragon” if not on the Plains of Megiddo then at least on the dance floor of a goth club. There’s also a Philip K. Dick reference for good measure: “The androids dream of electric sheep.” Though Ulver have long plied their trade in Europe, they only played their first U.S. show last year. If we do ever have another chance to see them live—no matter how long the wait—I’ll try to be one of the first in line.   v