Global climate change threatens the way of life as we know it (just ask Bill Nye for proof of that.) But not every ailment has an ointment as not every disaster has a solution. Snowpiercer examines a world where a fix-all mechanism for global warming has gone horrible awry and left the world as we know it in frosty tatters, where the only few survivors occupy a train that hasn’t stopped circling the planet for 17 years. It’s a bleak glance into a natural disaster the scope of which we can forecast but not prevent but the true terror lies not in the world outside the train, but the social order which takes hold within it. It’s a distinctly international story (with a cast that’s one gay guy shy of a Benetton ad) about standing up for what’s right and blowing shit up when it refuses to nudge. Rife with sociopolitical commentary and brimming with one-of-a-kind world-building, South Korean director Bong Joon-Ho looked like the perfect guy to take on a thinking man’s actioner of this breed. After all, who else would have dared to end this movie like he did?

When a Doc Brown of an experiment gone bonkers has blanketed the world in sub-zero temperatures and snowbanks the height of The Wall, the only survivors are forced to live out their existence on a deus-ex-machina of a bullet train called the Snowpiercer (from which the movie takes its namesake). The Earth we once inhabited is now one big snowy tundra, a white-washed arctic plains that you wouldn’t last a minute in without being transmogrified into a human popsicle as if from a spell cast in Frozen. While all forms of life outside the confines of Snowpiercer’s steel belly have turned to ice sculptures, the engine – a figure of Godlike worship – keeps the remainder of humanity shielded from the chilly blast of frozen-over reality lurking just outside.

Inside the Snowpiercer though, a new social order has taken form, mimicking the unjust class ladder of society’s past. Not an improvement of civilization pre-Snowpiercer so much a magnified extension of it, the sociopolitical climate inside this Energizer bunny of a train is as icy as the winter chills outside it. In the front, passengers throb in beat-dropping clubs and eat their bi-annual plate of sushi while the tail section contains a gang of inexplicably reviled third-class citizens; they’ve no voice in their destiny, sparse food aside from black, gelatinous bars and often no extremities. This seems to be because whenever these tailies act out, a toothy bureaucrat (Tilda Swinton) plugs a metal band around their arm and pops it out of the train. Rather than turning dark with frost bite, their snow-blasted limbs take on a White Walker cool and are promptly ice-picked from their bodies. It’s no question that social justice has no chance to spark amongst the ranks of the have-nots.

Their soot-faced languor and impossible quality of life catalyses an insurgency amongst the more able-bodied ranks, including Curtis (Chris Evans aka Captain America himself). Even in the face of C3PO-esque unlikely odds, this Winter Soldier has the brass to incite a doomed riot, leading a band of roguish anarchs that includes Jamie Bell, Octavia Spencer, and quite limbless John Hurt towards the Snowpiercer’s engine and their ultimate redemption.

Along the way, Joon-Ho’s customary political undercurrents rage strongly but his critique is more wide ranging – and potentially even more damning – this time round. Snowpiercer is not a condemnation of government misconduct and fallibility (see: The Host) but of humanity itself. His latest film seems to say that humanity and inequality exist in symbiotic harmony and that one simply cannot exist without the other. Darwin’s survival of the fittest has never felt so punitive.

The horrors of a socially enforced caste system are all the more distressing when magnified to this degree and Snowpiercer‘s cross section of inequality reveals spurring commentary on global disproportion that exists today. Sometimes you have to strip back the world to see the festering rot scurrying beneath and sometimes you have to cover it in ice to cull the warmth hidden inside. This way, it’s all the easier to pluck out the icy hearts that steer our world – or is it train? – towards a skewed and skewered social order from the fiery passion of human’s softer, more admirable side. It cuts in two ways: there’s always someone at the front of the train whose convictions have to be as chilly as their resolve in order to keep this train running. Is it then a coincide that injustice is spelled in just ice? (Sorry for the bad pun.)

And nothing speaks to this tattered circumstance more than the adroit set design from Ondrej Nekvasil who carves the train into reality without much use of CGI while amplifying the underlying themes of class oppression. If not entirely realistic (where do they all sleep?!?!), it’s still mighty impressive to behold and a lot of fun to journey through.

Using this mesmerizing set to the advantage of his storytelling is Joon-Ho’s strong suit just as his lack of knack for action is his Achilles’ heel. In the big spectacle scenes, his frantic camerawork proves that his ability to direct action leaves much to be desired. Though it may seem amiss to be complaining about these blockbusting portions of a movie clearly operating on more political tracks, the fact of the matter is that when Joon-Ho does take to showman scene work, he slips as if on black ice. And that’s not his only misstep.

The language barrier between him and his cast seem to have gotten the better of some scenes, with hammy dialogue that just doesn’t roll off the tongue throwing a palpable stick in the spokes. While some of the performers are better able to gnaw into the campy dialogue (see: Swinton and her scene-chewing chompers), others, such as Evans, look caught off guard and quite frankly look silly when spewing a mouthful of affected jargon. It’s a relatively minor complaint in a movie that sees a frickin’ never-ending train as the means for surviving the next Ice Age but it was a hang up I wasn’t able to fully ignore.

This all comes to a head when you really stop to dissect the many parts and pieces of Snowpiercer but – much like the train itself – I can’t help but admire what an unconventional product it really is. Joon-Ho is as eccentric a filmmaker as you can get – after all he did make a monster movie that shifted towards the South Korean government being the ultimate baddie. This being his first go in English with a cast of this caliber, it’s no wonder that he’s got a little slop-rock in his ballad. But even the finest of tunes have a wrong note here and there. As such, Snowpiercer‘s messy but beautifully imperfect. After all, you can’t have your ice-cream cake and eat it too.