Director: Wes Ball
Cast: Dylan O'Brien, Kaya Scodelario, Thomas Brodie-Sangster, Giancarlo Esposito, Aidan Gillen, Barry Pepper, Lili Taylor, Ki Hong Lee, Patricia Clarkson
Certificate: 12A

The Scorch Trials manages the impressive feat of containing more running than The Maze Runner, a film that was mostly about people running. The problem is that after escaping their labyrinthine prison at the end of the first film, our defiant teens need something else to run from. They take their lead from Marlon Brando's similarly rebellious Wild One: Whaddaya got?

At first, the answer seems to be a vaguely suspicious shelter for teens immune to the virus wiping out humanity. It's run by creepy-man-of-the-moment Aidan Gillen, whose job title is unclear, but mostly seems to involve curling the corner of his mouth every time someone gets hurt. You don't need to hear the words "paradise", "lucky chosen ones" and "never seen again" to guess things aren't all they seem.

When outside of the compound, though, that reason changes to the zombies now populating the planet - freaky, dull-eyed, black-veined creatures that don't waste time shuffling around like the Romero monsters of yesteryear. Or is it the humans trying to survive in this burned-out society, the kind of scavengers desperate enough to fire a gun, chain someone from the ceiling or sell out their friends? Perhaps it's the sinister organisation WCKD, which wants to harvest the kids for their cure-carrying blood?

Our teens spend the whole film rushing between this endless string of threats, stopping only to look shocked, surprised or remind each other to keep running. Dylan O'Brien remains likeable as leader Thomas, but is reduced to jogging to the end of the frame and staring, open-mouthed, into the distance at the next oncoming peril. The rest of the gang, meanwhile, rely on their actors' natural charm (Thomas Brodie-Sangster remains a talent to watch) to get through the script: the majority of the dialogue consists of the words "Quick!", "Run!", "You're almost there!" or a combination of the three.

Wes Ball directs it all, at least, with an impressive urgency; after tackling sci-fi with his first outing, he leaps into horror with the same energy and strong sense of world-building. The abandoned skyscrapers and eerie corpses are all brilliantly, creepily brought to life - although, despite being edited for a 12A certificate, this is really not suitable for those under 15. The newest members of the cast, meanwhile, are obviously having fun: Breaking Bad's Giancarlo Esposito is enjoys himself as, essentially, a desert pirate, while Lili Taylor tries to bring gravitas to the film's science as a former member of WCKD - you can tell a company is bad when their name is one letter away from a lucrative sponsorship deal with an alcoholic beverage. The excellent Kaya Scodelario, meanwhile, out-acts them all as Teresa, who becomes increasingly conflicted over the whole situation.

But the threads holding the plot together are woefully thin: Rosa Salazar is wasted as a token romantic interest, who is introduced just for the sake of having a love triangle, while Alan Tudyk's role as a sleazy bar owner could have come from a completely different film - another person inserted solely to extend the runtime. There's much to be said for a film aimed at younger audiences daring to tackle the same moral dilemmas as Channel 4's brilliantly dark series, Utopia - the use of the divided ensemble to foreground the debate of the kids' lives vs the future of the world is effective - but writer TS Nowlin is so busy being ambitious, he forgets to be entertaining. This is a big step down from The Maze Runner's taut, gripping structure: the maze, not the running, was the secret to that film's success. Here, our heroes even flee from the weather in a scene that brings to mind Mark Wahlberg trying to outrun the wind in M. Night Shyamalan's The Happening. Without the confines of the franchise's maze walls, this sequel dashes all over the place - but it feels slower than ever.