There's little mystery about "Journey 2: The Mysterious Island."

This 3-D sort-of sequel wears its formula-for-dollars purpose with pride, delivering a dash of cinematic nonsense that represents Hollywood calculation at its shrewdest and most shameless.

Again poking Jules Verne's remains with a sharp stick, the producers of the 2008 hit "Journey to the Center of the Earth" present their second modern take on the 19th century fantasist's wild stories. And "Mysterious Island" is every bit the amusement park ride cloaked as a movie that the first "Journey" was, the new flick stranding a misfit band of adventurers on Verne's lost island of freakish creatures.

What this one lacks by comparison is the relative novelty of digital 3-D, which was in its infancy for mainstream theatrical releases when "Journey to the Center of the Earth" came out.

It also lacks the likable goof factor of Brendan Fraser, who starred in the first movie but isn't back for the second. Dwayne Johnson steps in this time, and while he tries to yuck it up amid the nonstop action, he's just not a goofball on the order of Fraser, who somehow can make extreme silliness palatable with that big, simpering grin of his. Johnson, on the other hand, merely simpers.

"Journey 2" also features a change of directors, with Brad Peyton ("Cats & Dogs: The Revenge of Kitty Galore") overseeing a collection of impressive but annoying visuals, serving up gimmicky 3-D that's continually trying to poke things in your eye.

Johnson stars as ex-Navy guy Hank, stepfather to troublesome teenager Sean Anderson (Josh Hutcherson, reprising his role from the first "Journey").

In its rushed and clunky opening minutes, "Journey 2" establishes that Sean's a bad boy genius who resents his stepdad; bonds the two in a scene that shows Hank's an OK guy and Sean's not such a bad boy and not such a genius; sends them off to the South Pacific in search of Sean's grandfather (Michael Caine), who sent a cryptic transmission that he had found Verne's supposedly fictional island; and lands them in the company of helicopter pilot Gabato (Luis Guzman) and his beautiful daughter, Kailani (Vanessa Hudgens), who ferry the visitors to the remote isle.

Peyton and cousins Brian Gunn and Mark Gunn, who wrote the screenplay, waste no time giving the characters more than the barest cartoon personalities, allowing the filmmakers to focus on the movie's only reason to exist. And that's purely as a thrill ride, the actors racing from a giant lizard, flying on monster bees while pursued by colossal hungry birds, rushing to escape an enormous electric eel.

Size matters to the filmmakers here, which might be why they signed up Johnson, a co-producer as well as star, who strains for some laughs with an overdone gag about his massive pectoral muscles.

The actors make an effort with the interminable repartee they're given to mutter, but the presence of actors as good as Caine and Guzman only highlights how dreadful and dumb the banter is ("Journey 2" will be preceded by a new Daffy Duck cartoon; that short didn't play before a recent critics' screening, but we're betting its dialogue will be sharper than the main attraction's).

The 3-D images have improved greatly since the first "Journey," but even more this time, the filmmakers play a game of "made you flinch" with cheap shots of objects hurtling off the screen. Good for a giggle at a theme park attraction, good for some groans and grousing when paying a 3-D premium to park your carcass in a theatre for 90 minutes.

There's promise of more, too, the movie hanging out the prospect of a "Journey 3" inspired by another of Verne's sci-fi classics.

The root of the franchise is kind of clever, updating Verne's novels to our times by pretending they weren't fantasies but chronicles of actual expeditions. And "Journey 2" has its heart in the right place as a family-friendly adventure that might interest some kids in checking out Verne's books.

If only the movie had the hint of a brain.

One and a half stars out of four.