While Governer A. Schwarzenegger summons up all his legendary might and braces himself for battle with feisty eco-warriors over his inability to protect California’s salmon stock, the fate of the Terminator franchise now lies in the hands of bolshy method man Christian Bale and excitably trashy director McG and their reboot of the legendary spectacle factory.

Moving the battleground from the present to the future, Terminator Salvation find the adult John Connor (Bale) seeking an end to the war between man and machine, while seeking to ensure the time-travelling events of the previous movies aren’t halted, thus throwing a spanner in his whole saviour-of-mankind routine.

Into the mix comes Marcus Wright (Sam Worthington), a condemned man who gave his body over to the Skynet Corporation while on death row. Part-man, part-cyborg, Marcus seems to hold the key to the resolution of the war and the fate of John Connor – but can he be trusted?

The Terminator movies have rightly achieved iconic status. While being symptomatic of the puffed-up grandeur of the 80s, they also helped to shape the modern event movie – Terminator 2 set a high watermark for CGI that others followed. But as movie-making technology has accelerated in recent years, has it ironically left no room for the daddy of techno-futurism?

With James Cameron away from the project, Charlie’s Angels director McG calls the shots. While other music video director-turned film directors have shown an imaginative flair for storytelling – think of Michel Gondry’s Eternal Sunshine and Spike Jonze’s Being John Malkovich – McG sadly only appears to have a propensity for highly glossy, well-framed visuals that mask a lack of depth or character.

This isn’t helped here by the casting – Bale’s now-legendary meme-inducing antics during the filming of this paint him as an unlikeable individual in real life, and on-screen his performances all seem to hover around the blandly sullen mark – here he goes for blandly sullen with a gruff voice.

Such is his tepid turn that he increasingly becomes an irrelevance throughout the film, marginalised by a showing from Worthington that grows as the movie progresses – he redeems the film by neatly giving nuance and a sense of depth to the angst-ridden manborg trapped between the warring factions.

With a story that lacks any mental depth beyond the logic conundrums that underpinned the originals, Terminator Salvation is reliant on its set-pieces for impact – and even here it falls sadly short. There’s a lack of dynamism to the pyrotechnics – the sole defining feature of the SFX here is often the size of them, not the impact of them. As monumental terminators and ships come crashing down, there’s little in the way of invention to sell them, you’ve seen it all done better elsewhere, from the Matrix right up to Transformers – in short, jaws will stay firmly in the upright, non-dropped position.