CULT OF LUNA have a confession to make.

Turns out the "true story" behind the Swedish group's most recent LP, 2008's "Eternal Kingdom" - something to do with a mad man's diary, filled with ramblings about a fantasy world, unexpectedly surfacing in their rehearsal space - was in fact entirely fabricated, as seems all too obvious, in retrospect.

However, they now want us to believe that the inspiration for that album's belated successor, 2013's "Vertikal", originated in Fritz Lang's dystopian 1927 science-fiction film "Metropolis" - yeah right, pull the other one, why don't you?

All kidding aside, though, and of perhaps far greater importance, in the five years since CULT OF LUNA's last LP, the world has kept right on turning, turning, turning - possibly too quickly for the Swedes to keep up and remain creatively relevant.

After all, the admittedly amorphous musical genre under which they'd previously been categorized (for good or ill) has since fallen far enough out of commercial and critical favor that no one is even sure what to call it anymore: post-metal, metalgaze, progressive sludge-core, Honey Boo Boo?

So it's to CULT OF LUNA's immense credit (and their fans' relief!) that, rather than despair over this hiatus and attempt to move with the times or, worse, simply guess which way the wind may blow next, they've chosen instead to be just as they were: inventive, long-winded and unpredictable, to be sure, but recognizably so to listeners who liked them in the first place.

If anything, the band has in fact "regressed" into braver experimentation on this, their sixth album, since "Eternal Kingdom" had in many ways tempted the limits of their sound's commercial accessibility, while new "Vertikal" offerings such as "I: the Weapon" and "Mute Departure" see the band sparing no thought to editing their protracted textural explorations, most of which familiarly boast hypnotic, bass-driven riff foundations a la TOOL over which mellifluous melodies can glide and evolve untethered, or at least until they are violently smacked down to earth by thunderous metallic punctuations.

In the case of the awe-inspiring, all-time career epic, "Vicarious Redemption", that slow-building compositional template emerges covertly out of dense underbrush fit to soundtrack to the latest Tarzan flick, before cresting magnificently amid power chords and scintillating melodic guitar and keyboard runs bearing a cathartic payoff akin to AGALLOCH's uber-epic, "Black Lake Nidstang".

If anything, these movements rumble and pulse with so MUCH palpable human emotion (more ominous than hopeful, but emotional nonetheless) that they might even call the band's "inspired by 'Metropolis'" claims into question, were it not for the helpful scene-setting of robo-synthetic interludes like "The One", "The Sweep" and "Disharmonia", plus deeper techno-mechanical sound integrations in "Synchronicity", "In Awe Of" and farewell lament, "Passing Through".

None of which diminishes the scale of CULT OF LUNA's artistic accomplishment across "Vertikal" - not least for reaffirming the band's talents with such a compelling and impressive suite of songs - arguably as strong as anything in their discography - but also renewing their lease on life for years to come, wherever and whenever they should wish to pursue it.

The wait was well worth it.