Sequel shows surprising divergence

“Insurgent” doesn’t seriously diverge from the “Divergent”/ “Hunger Games”/ “Maze Runner” formula until its final act.

Up until then, this “Divergent” sequel is Young-Adults-Save-the-World generic. It’s action-packed in the extreme, as Young Heroine Tris (Shailene Woodely) and “Dauntless” hunk Four (Theo James) run from the armed, motorized thugs that the smug Erudite elitists send after them, with barely time for a betrayal, a moment of weakness and a break for Tris to pile on more makeup and lip gloss.

Not everyone is brave or true enough to make a revolution work. But there’s no excuse for not looking your sexiest.

The blossoming Tris-Four love affair is expedited by the terror of the chase and the convenience of zippered jumpsuits.

New Factions are visited, with Octavia Spencer’s Joanna controlling her temper in leading the tolerant sweethearts of Amity, who briefly shelter our heroes.

“Go, with happiness!”

Candor leader Jack Kang (Daniel Dae Kim) is indeed candid, and that translates as just, too. A fierce Naomi Watts introduces us to the scheming/fighting Factionless. It’s all part of the endless exposition in this post-“Harry Potter”/ “Twilight” teen and tween film universe. There are always new factions, or factionless folk, to introduce and explain.

But this derivative fluff, memorably mocked (along with its myriad young-adult sci-fi cousins) last fall on “Saturday Night Live,” takes a turn toward interesting the moment Tris, haunted by memories of her slaughtered family, tells us how she wants this insurgency to end.

“We need to kill Jeannine.”

The Divergent girl has become a hardened revolutionary, and she wants the leader (Kate Winslet) who killed those she loved to die.

At that point, director Robert Schwenktke (“Flightplan,” “RED”) and his screenwriters begin to transcend the material, something it took “The Hunger Games” longer to manage. We might think of the Arab Spring or the French Revolution and remember that not every insurgency leads to positive change, that every faction will have blood on its hands, and that, in armed revolts, might makes right, but not righteous.

The wondrous Woodley is a more convincing tough chick here, James blandly adequate in support, Miles Teller a colorful third wheel and Ansel Elgort (as Tris’ meek brother) is a colorless fourth wheel.

The fights are well-staged, the chases dull.

But as “Insurgent” wraps up, it picks up speed and depth, and gives you hope that maybe this series won’t conclude as the copy-and-paste “Hunger Games” it has felt like, from the moment the books were word-processed onto the best-seller lists.