Barrelling along from one cliff-hanging episode to the next, Maze Runner: The Scorch Trials, second leg of the trilogy of post-apocalyptic fantasy adventures based on young adult novelist James Dashner’s bestselling books, barely gives its young protagonists – or the viewer – a chance to catch breath.

Despite the breakneck pace and labyrinthine story, we soon get the gist of what is going on. Dylan O’Brien’s 16-year-old hero Thomas and his fellow teenage survivors from the first film’s perilous Glade, including Teresa (Kaya Scodelario), Minho (Ki Hong Lee) and Newt (Thomas Brodie-Sangster), have been plucked to safety by agents of enigmatic organisation WCKD, but it doesn’t take them long to work out that their rescuers are up to no good.

Escape from their designated role as lab rats, however, takes them into The Scorch, a blasted landscape of scalding deserts and ravaged cities, the remnants of a world devastated by solar flares. And as the teens strive to reach a possibly mythical safe haven, there is no let up in the hazards they face.

It’s thrilling stuff. Working with a bigger budget this time, returning director Wes Ball pumps up the action, delivering exhilarating sequences of flight and fight, including a heart-pounding chase through a ruined mall in which the gang are pursued by zombie-like Cranks, victims of the disease to which the youngsters alone are immune. The precise ins and outs of the story (Why? How? What?) remain elusive and the plotting does get overly tortuous at the end, but O’Brien and his co-stars provide enough collective charisma to ensure we’ll be back for their final dash.

Certificate 15. Runtime 131 mins. Director Wes Ball.