REVIEW: The Divergent Series: Allegiant (12A) **

Anyone who believes that Americans don’t grasp irony should watch the third film in the Divergent saga, adapted from Veronica Roth’s best-selling trilogy for young adults.

While the series’ gutsy heroine makes speeches about individuality, Robert Schwentke’s dystopian action adventure surrenders to bland genre conformity.

Allegiant lurks in the shadow of The Hunger Games, treading water for two hours before lighting the fuse on a final reckoning that forms the spine of the concluding instalment, Ascendant, released in June 2017.

Unlike Katniss Everdeen, Divergent’s trailblazer Tris becomes increasingly reactive in this third outing.

She develops a nasty case of naivete at a critical juncture, which doesn’t make sense given all she has endured.

The demise of Jeanine (Kate Winslet) in the second picture leaves a power vacuum, which is neatly filled by Evelyn (Naomi Watts), embittered leader of the factionless, and Johanna (Octavia Spencer), figurehead of peace-loving Amity.

‘Sometimes walls are there to protect us,’ Evelyn tells her people, but Tris (Shailene Woodley), her lover Four (Theo James), brother Caleb (Ansel Elgort), good friend Christina (Zoe Kravitz) and Dauntless turncoat Peter (Miles Teller) disagree and scale the electrified perimeter of Chicago.

They discover a radiation-ravaged wilderness known as The Fringe where rivers run blood red.

Armed forces rescue Tris and her group in the nick of time and transport them to headquarters.

There, facility director David (Jeff Daniels) reveals a grand genetic experiment with far-reaching consequences for the fate of mankind.

Unsure who to trust, the new arrivals face difficult choices to survive.

Meanwhile back in the city ruins, Evelyn and thuggish henchman Edgar (Jonny Weston) prepare to usurp Johanna.

The Divergent Series: Allegiant is the weakest link in the dramatic chain.

Four screenwriters offer no artistic justification for cleaving Roth’s final book in half: Allegiant is two hours of awkward foreplay and at the end.

Action set pieces are solid but functional.

Teller serves up quips as the comic relief and only justifies his presence in a laughable action sequence that witnesses hundreds of extras fleeing from memory-erasing orange gas that looks like the special effects department unleashed a giant carroty fart.