Although shot and projected in 3-D (and also available on Imax screens), this sequel to 2008's "Journey to the Center of the Earth" can be described as both leaden and insubstantial. Implausible without being fantastical, it labors to evoke awe or wonderment.

In its defense, the movie does transmit a positive view of humankind's quest for scientific knowledge and instinct for adventure. And it's mostly a wholesome affair, though marred on that score by a somewhat casual attitude toward youthful sexuality (typified by overly sensual shots of a young adult female character) as well as by a few potty jokes.

The sense of mystery the filmmakers attempt to extract from their literary source material is diluted by a strained premise and especially lame expository dialogue. This would be less of an impediment if the movie offered superior visual thrills, yet the technical credits are merely serviceable.

When 17-year-old Sean Anderson (Josh Hutcherson) receives a distress signal he believes was sent from an uncharted island, his new stepfather, Hank (Dwayne Johnson), helps him decode it using Verne's book "The Mysterious Island," Robert Louis Stevenson's "Treasure Island" and Jonathan Swift's "Gulliver's Travels."

Supposedly, all three authors had the same land mass in mind when fashioning their stories. Sean also believes this isle is where his missing grandfather, Alexander (Michael Caine), can be found.

Hoping to improve his relationship with his hostile stepson, a skeptical Hank offers to help Sean locate the place. They travel to Palau in the South Pacific and — after surviving a maelstrom in a rickety helicopter flown by tour guide Gabato (Luis Guzman) — arrive on the island with Gabato's daughter Kailani (Vanessa Hudgens) in tow.

There they encounter strange natural phenomena such as a gold-spewing volcano and giant bumblebees, along with other surprises. Unfortunately, the island is rapidly sinking back into the sea and the quintet (Alexander is indeed in residence) must race to escape using the submarine Nautilus, which Verne wrote about in "Twenty Thousand Leagues Under the Sea."

Serendipitous fantasy, whether on the page or the screen, requires a certain amount of plausibility and coherence to capture the imagination. An excess of pseudo-scientific jargon and unfunny banter undercuts the appeal of "Journey 2."

Rather than develop substantive themes or get entertainingly lost in the action, director Brad Peyton, working from a script by cousins Brian and Mark Gunn, focuses on tension between Hank and Alexander. Guzman's infantilized character is also overused as comic relief.

A four-minute cartoon starring Daffy Duck and Elmer Fudd precedes the movie; it's replete with the kind of gun-related violence familiar to anyone who grew up watching Looney Toons animation.

On the whole, potential moviegoers would be better advised to stay home and read the above-cited classics.

The film contains some teen sensuality, several moderately scary sequences, a few uses of suggestive language and occasional toilet humor. The Catholic News Service classification is A-II — adults and adolescents. The Motion Picture Association of America rating is PG — parental guidance suggested. Some material may not be suitable for children.

*****
John P. McCarthy is a guest reviewer for Catholic News Service.