Grade: D

Moving from the sublime to the ridiculous, Guillermo del Toro follows up his well-deserved Oscar winner “The Shape of Water” by acting as one of the producers of this laughable sequel to his bloated 2013 “Power Rangers”-meets-“Transformers” ripoff, “Pacific Rim.” His direct responsibility is minimal: the script was written by others, and he handed over directorial duties to feature neophyte (and co-writer) Steven S. DeKnight, whose earlier claim to fame rests on his contributions to television, including various incarnations of the Starz “Spartacus” series. DeKnight’s efforts are workmanlike, but he’s no del Toro—or even a Michael Bay.

And del Toro still bears the burden of having conceived the nutty premise in the first place. Of course, it can be argued that the premise to “Water” is no less nutty, perhaps even more so. Presumably the secret is all in the telling. If so, it’s not told especially well in this case.

The time is a decade after the battle between the alternate-dimension kaijus, giant lizards unleashed from breaches in the ocean floor, and the two-pilot giant robots, the jaegers, that humans build to defeat them, with ultimate success. A rogue jaeger appears in Australia just as a decision is taken by the Pan Pacific Defense Force to replace the pilot-bearing jaegers with drones controlled by overseers back in a control room, and the old jaegers must be called back into action. Eventually the lizards reappear as well, and city-destroying action is once again on the menu. The locus of the big finale is none other than Mount Fuji, which is a kaiju target for reasons that are explained in typical meaningless gobbledygook.

Within that larger context the script focuses on Jake Pentecost (John Boyega), the son of Stacker (played by Idris Elba in the previous film), one of the heroes in the first war (and an ex-pilot himself) who’s turned criminal. After a job gone wrong, he encounters a spunky orphan named Amara (Cailee Spaeny, irritatingly shrill) who’s rebuilt a jaeger she calls Scrapper, and after a skirmish with a larger robot the two of them are taken into custody by the authorities. To avoid jail he reluctantly joins the pilot force again, and she enthusiastically becomes a cadet.

The other cadets are a pretty colorless lot, but there is one other pilot of note: Nate (Scott Eastwood), Jake’s old partner, who urges him to recapture his old sense of duty. Naturally they will become comrades-in-jaeger again as the battle starts, while Amara, though at once point expelled for insubordination, will be recalled to service and ultimately prove central to victory.

But there is a serious issue about that rogue jaeger and the new breaches for the kaijus to come through. They suggest that there is a human traitor assisting the enemy. Who might it be? The imperious head of the Shao Corporation (Jing Tian), who’s implementing the drone program? Or her loud-mouth lackey Newt (Charlie Day), the right-hand man in its development? Certainly it couldn’t be Jake’s half-sister Mako Mori (Rinko Kikuchi), a stalwart of the defense force, or Jules (Adria Arjona), the pretty pilot both Jake and Nate look at longingly, or Hermann Gottlieb (Burn Gorman), chief PPDF scientist and a genius at coming up with innovations just when they’re needed. Or could it? If you don’t care for any of those choices, there are plenty of other suspects—pilots, cadets, commanders, politicians and corporate types—lurking in the background to choose from.

As it is, the movie reveals the culprit pretty early on, and while there will be no spoilers here, rest assured it isn’t Jake, whose transition from antihero to pure hero Boyega limns with lots of bluster but surprisingly little charisma. It’s not really his fault, though: Jake is the sort of fellow who proclaims that he’s not going to give a stem-winding speech to his fellow pilots before the life-or-death battle, but then does just that, and then closes his spiel with the words “Let’s do this!”—an injunction that by now should be banished from every screenwriter’s lexicon.

At that Boyega is still miles ahead of Eastwood, the second syllable of whose surname is all too apt, or Day, whose animated ranting grows tiresome after only a few minutes, or Gorman, whose mugging would have been out of place in the days of the silents. Jing’s icily officious corporate mogul is only one of the picture’s efforts to appeal to the huge China market, which was instrumental in the financial success of the first movie and will obviously be crucial this time around as well.

On the technical side the most notable aspect of “Uprising” is the ear-blasting mix of Lorne Balfe’s score and the sound design. Dan Mindel’s cinematography is okay, but blighted by an avalanche of CGI that’s frequently murky and, even at its best, distinctly second-rate. Then there’s the frenetic tempo, courtesy of a trio of editors—Zach Staenberg, Dylan Highsmith and Josh Schaeffer. At least they bring the thing in under two hours.

A postscript to the movie threatens another sequel. The returns from China, of course, will be decisive in determining whether that’s just another fantasy.