THE strong first film in the dystopian young adult fantasy franchise, based on James Dashner’s best-selling novels, took an elegant premise and ran with it: a young man named Thomas (Dylan O’Brien) wakes up in a mysterious giant maze with a severe amnesia and must work together with the other “Gladers” trapped inside to find a way out.

That led to an underwhelming sequel, The Scorch Trials, which opened things up physically but ironically restricted the creativity as it blended into the crowd of both its own genre and zombie-esque horror that has risen to prominence in TV and film in recent years. Thankfully the third and final instalment arrives to give us a solidly satisfying and resolutely action-packed conclusion to the saga.

This picks things up a few months after the events of the last film – there’s no hand-holding explanatory title card here – in a world desperately in need of a cure for the “Flare” virus that has devastated most of the population.

Having long escaped the titular maze, Thomas and his friends Newt (Thomas Brodie-Sangster) and Frypa (Dexter Darden) team up with freedom fighter Vince (Barry Pepper), black market trader Jorge (Giancarlo Esposito) and his protégé Brenda (Rosa Salazar) to fight back against the all-powerful government group WCKD.

In a thrilling sequence that chucks you in at the deep end and sets the tone for the rest of the action to come, they pull off a daring train heist to rescue friend Minho (Ki Hong Lee) who is being transported with a group of other captured youngsters. But despite it going relatively according to plan, there still exists those held captive in WCKD’s stronghold facility at the centre of the Last City where they are undergoing tests to discover their immunity to the virus.

Our band of misfit heroes then head off to save humanity through zombie-infested territory ready to force their way into the facility where Thomas’s estranged friend Teresa (Kaya Scodelario) is now helping the baddies like Ava (Patricia Clarkson) and the gun-toting Janson (Aidan Gillen), a mission that could hold the key to humanity’s salvation.

This series has always had a certain extended chase mentality about it and while that’s still the case here, you feel the danger and menace of what the group is up against far more than ever. Stalwart director Wes Ball proves his ability to handle spectacle that makes it feel like it has a way bigger budget than it does, delivering punchy action that packs a wallop and is attuned to a strikingly unrelenting pace sustained across a lengthy 140-minute runtime.

There remains the niggling issue of its main character being quite thinly written and thus, despite the best efforts of O’Brien, is much less interesting when compared to the conflicted and empowering Katniss Everdeen from the genetically similar Hunger Games.

There are also some irksome logic holes that are glossed over (the supposedly impenetrable Last City seems fairly easy to break into, for example) and some disappointing squandered potential spotted throughout, not least series newcomer Walton Goggins being utterly wasted as facially disfigured resistance leader Lawrence.

But on top of the impressively weighty action there’s undeniably compelling character dynamics going on, particularly in how the film handles the fractured relationship between Thomas and the seemingly treacherous Teresa. And it contains the series’ most effective attempts yet at exploring themes of bonded friendship, the struggle of society’s disenfranchised and the primal human need to survive against all odds.

While not exactly a ground-breaking full stop, it’s nevertheless an involving and oftentimes genuinely thrilling finale achieved with a surprising level of bravura and just enough heart to make us care.