Early on in “Thor: The Dark World,” the latest slab of briskly amusing, elaborately inconsequential 3D entertainment from the Disney/Marvel comicbook factory, an evil Dark Elf announces his sinister plan to “unleash the Aether.” What sounds at first like an arcane euphemism for breaking wind turns out to be just another way of stating what you probably already suspected: The megalomaniac of the month is about to activate the latest all-powerful weapon capable of triggering mass annihilation, necessitating yet another intervention by a popular superhero and his ragtag band of sidekicks. Still, as helmed by Alan Taylor, this robust, impersonal visual-effects showpiece proves buoyant and unpretentious enough to offset its stew of otherwise derivative fantasy/action elements.

The fact that much of the action plays out in Asgard and other far-flung dimensions makes for an enlivening change of scenery at the very least, even if the film’s formula of destructive mayhem plus tongue-in-cheek humor remains pure essence of Marvel. Already expected to outpace 2011’s Kenneth Branagh-helmed “Thor” when it begins its international rollout Oct. 30 (with a Stateside bow to follow Nov. 8), the Disney release should rep an even more conclusive test than “Iron Man 3” of “The Avengers” effect, revealing just how massively Marvel’s individual franchise properties stand to capitalize on spillover success from that 2012 worldwide smash.

An ancient prologue recalls the battle between the noble forces of Asgard and a wicked race known as the Dark Elves, named less for their pale complexions than for their love of all-consuming darkness. But their dastardly plans are thwarted when they failed to detonate the Aether, an “ancient force of infinite destruction” that resembles a mass of writhing red energy-tendrils, or perhaps a plate of radioactive spaghetti. The surviving Dark Elves, led by the supervillain Malekith (an unrecognizable Christopher Eccleston), are sentenced to centuries-long slumber, while the Aether is buried deep down in a place where nobody would ever find it.

Centuries later, of course, who should stumble upon it but Jane Foster (Natalie Portman), Earth’s most beautiful astrophysicist and the mortal soul mate of everyone’s favorite hunk with a hammer, Thor (Chris Hemsworth). When her body unwittingly becomes the Aether’s host, making her the target of the newly revived Malekith, Jane is spirited away to Asgard by Thor, who is due to succeed his father, Odin (Anthony Hopkins), as king of the realm. But the coronation will have to wait, given that the Dark Elves’ plot to activate the Aether could have devastating consequences for all Nine Realms.

Earth, as it happens, is one of those Nine Realms, although if “Thor: The Dark World” is to be believed, it’s such a tedious planet that it’s hard to feel any sorrow at the prospect of its destruction. (If only it seemed like more than an idle threat at this point.) Things turn leaden almost every time the film cuts to terra firma, where Jane’s endlessly sarcastic friend/assistant Darcy (Kat Dennings) and new intern Ian (Jonathan Howard) try to figure out a scientific solution with the help of Jane’s old mentor, Dr. Erik Selvig (Stellan Skarsgard), who seems to have added crazed nudism to his list of eccentric hobbies.

Fortunately, the strained comedy and mundane visuals of the Earth scenes (all of them set in London, where the film was largely shot) are rarely in evidence in Asgard, and it’s largely a pleasure to spend time there with Thor and Jane, who looks especially charming clad in the finery of the realm (courtesy of versatile costume designer Wendy Partridge). It’s in this otherworldly kingdom — variously influenced by Norse mythology, brutalist architecture and Mandalay Bay — that director Taylor delivers his most compelling setpieces, starting with the Dark Elves’ deadly assault on Odin’s palace and culminating in a rather stunningly beautiful mass funeral sequence.

Asgard, too, is where we again find Thor’s treacherous, power-mad brother, Loki (Tom Hiddleston), now languishing in an underground prison after his role in the events of “The Avengers.” Loki may be a known quantity by now for Marvel fans, but he’s rarely been more delectable company than he is here — defeated, bitterly sarcastic and utterly indifferent to either his own fate or Asgard’s imminent destruction. The brotherly enmity between him and Thor takes a genuinely intriguing turn when it becomes clear the two will have to join forces in order to stop Malekith, a development that is wisely played for laughs as well as tense character drama.

In the end, that humorous approach is largely the film’s saving grace, keeping the action sufficiently lively and diverting that audiences won’t recognize how recycled the material is, or how low the stakes feel. Disposable as it may feel at the end of the day, “Thor: The Dark World” is not without a certain pleasing deftness, from its goofily offhand way of finding scientific explanations for blatantly supernatural phenomena, to the blithe ease with which it sends its characters hopscotching from one dimension to the next. This latter motif succeeds in turning film’s climactic showdown into a playful exercise in physical displacement, shot and edited with a bit more coherence than the typical f/x orgy of exploding buildings. And a few neat twists throughout hinge on the Asgardians’ talent for shapeshifting, which functions here like the magical equivalent of characters peeling off latex masks a la “Mission: Impossible.”

With no sins of hubris to overcome this time around, Thor himself is a somewhat duller presence this time around, through no fault of Hemsworth’s solid, likable performance and stereoscopically enhanced pectorals. Portman makes a fine damsel in distress, pausing every so often to frown down at meteorological gadgets or to flash her color-tinted contact lenses as the Aether burrows its way into her system. Rene Russo’s touching turn as Odin’s brave wife, Frigga, offers a welcome respite from all the brooding male tempers on display, while Idris Elba somehow animates his largely inexpressive role as Heimdall, the all-seeing guardian of Asgard.

That there are not one but two obligatory teasers buried in the closing credits merely underscores the merrily-we-roll-along assembly line that Marvel’s movie output has become. Up next, for the record: “Captain America: The Winter Soldier” and “Guardians of the Galaxy” in 2014, followed by “The Avengers: Age of Ultron” in 2015.

(EDITOR’S NOTE: An earlier version of this review supplied details about the film’s coda. They have been removed.)