"Allegiant" is the kind of movie where, when a character says, "We're gonna be OK," you know her troubles are just beginning. Especially if that character's name happens to be Tris Prior.
As sturdily played by Shailene Woodley in two previous films with one more yet to come, Tris is a young woman who's had a lot to contend with as the heroine of the "Divergent" series of adaptations of Veronica Roth's mega-selling young adult novels.
These books have such a devoted audience that the final book in the series, like "Harry Potter" and "Hunger Games" before it, has been split into two films.
This first part is mildly diverting, unsophisticated fare that takes liberties with the original novel yet still stumbles on confusing exposition that doesn't really make complete sense even when it's taken from the book.
When last we left the intrepid Tris at the close of the previous "Insurgent," evil Janine had been vanquished and the citizens of the futuristic ruin that was once the great city of Chicago are headed for the wall that encircles them and keeps them from whatever is on the other side.
Not so fast, says director Robert Schwentke, who's returned from that last effort. Before showing us what's on the other side of the wall, he and a brand-new trio of screenwriters (Noah Oppenheim and Adam Cooper & Bill Collage) take a little time to reveal how bad things have gotten even after Janine's death.
For starters, de facto new ruler Evelyn (Naomi Watts), undaunted by rival Johanna (Octavia Spencer), is putting on the equivalent of Stalinist show trials before a blood-thirsty mob angry about an old regime that divided everyone into factions.
"You've incited a mob. Good luck controlling them," says her son Four (Theo James), who does double duty as Tris' beau, in a good example of the film's comic-book dialogue. (Evelyn's response, "I'm doing this for you," is just as feeble.)
Fed up with all these bad vibes, Four, Tris, Tris' brother Caleb (Ansel Elgort), her gal-pal Christina (Zoe Kravitz) and all-around slimeball Peter (Miles Teller) manage to get over the wall and confront what's on the other side.
Initially, it's not a pretty picture but, rather, an enormous toxic waste dump area unappetizingly called "The Fringe." But then our heroes run into some slickly dressed types who announce, kind of like an old ad for G.E., "Welcome to the future. We've been waiting for you."
The future turns out to be an ultramodern citadel called the Bureau of Genetic Welfare, established in what used to be Chicago's O'Hare Airport and run by the unctuous David (an underutilized Jeff Daniels). Tris may think she's safe here, but we know better.
The tale that David tells her about the origins of the old faction-dominated system back home in Chicago, a perplexing saga involving wars caused by genetic modification, an experiment that has lasted 200 years and the difference between pure and damaged genes, is far-fetched even by the standards of the genre, not to mention confusing.
No matter, because the high school-style emotions that are the story's underpinnings are never far from sight. Tris, for reasons that are unclear, spends more and more time with David, causing Four to feel peeved. Will attractive Bureau resident Nita (Nadia Hilker) catch his eye? Stay tuned.
As directed by Schwentke, who did the more involving "Insurgent" but won't be returning for the final film, "Allegiant" has its share of brisk action and high-tech gizmos like drones that obey finger commands.
But because the series' plot reveal turns out to be more confusing than compelling, and because turning a novel into two films invariably leads to inflated productions, only the most devoted fans of the book will pledge allegiance to what's on the screen.
'The Divergent Series: Allegiant'
MPAA rating: PG-13, for intense violence and action, thematic elements, and some partial nudity
Running time: 2 hours
Playing: In general release