First, the good news: after Insurgent – aka Divergent 2 – tapped out that grey, sim-city-fighting mood, this shiny threequel abseils over the giant wall surrounding dystopian Chicago and smartly drops us into a vibrantly scarlet, Martian-looking landscape, where even the toxic rain is red. Director Robert Schwentke even kicks the enjoyably sub-Mad Max extreme-sport action sequences into a higher gear than previous instalments.
But he’s banjaxed when the plot dictates that Tris (Shailene Woodley) and her fellow rebels are whisked to CGI-laden genetic-engineering biodome The Bureau. Here, the high-school hokum of the Divergent 'factions' becomes high-tech eugenics, as kindly director David (a twinkling Jeff Daniels) determines that only Tris’ ‘pure’ genes can save blighted mankind.
Always fond of pseudo-science and ethical quandaries, the Divergent series reaches a new, mildly pretentious peak here. There’s even a double-helix Bureau staircase, to underline the science-y symbolism. But its sort-of topical themes of genetic exclusion, surveillance, racism and ignoring neighbouring conflict (Chicago is riven by tribal warfare between the Factionless and those 'Allegiant' to the old system) don’t translate into meaty exploits.
Instead the film favours wide-eyed wrangling between Tris and boyfriend Tobias (Theo James, positively square-jawed with righteousness). The chief joy of the series, Shailene Woodley’s tenacious but vulnerable Tris, seems to be unusually Redundant, sidelined into ‘pure’ passivity while Tobias is Resurgent, muscling through mysteriously violent Marine-style Bureau raids like an action hero. Still, his racing around stops the film flopping too frequently into the repetitive rows that replace heated clinches this time out.
Splitting the final book into two movies (Ascendant is due next summer) should have given Allegiant endless plot possibilities to play with. Instead it drags out the Bureau business, with only the eye-candy compensations of cool space-age kit (drone-led gun battles, spaceship crashes, VR surveillance pods).
And though we're asked to invest in the fate of the Chicago inhabitants as well as Team Tris, we see only slivers of the Allegiant vs Factionless war. Nowhere near enough action, then – but at least the ending is an absolute gas…