After much debate about what cut American audiences would see of Bong Joon-ho's English language debut, Snowpiercer is here and it's chilling, mesmerizing, and absolutely sensational.

Loosely based on the French graphic novel Le Transperceneige, Snowpiercer takes place in a not-so-distant future where the Earth has been quickly overtaken by a new Ice Age. All life has been wiped out as cold and has overtaken every continent – that is, save for those few remnants of humanity who made it aboard Snowpiercer, the titular train that ceaselessly circles the globe while its insides fester with class conflict and revolt. Eighteen years have passed since the last scraps of humanity boarded this massive vessel, and while those in the front live lives of luxury – enjoying sushi and spa treatments – those in the back are forced to fight for space and feed on an uninviting brown brick of gelatin called a protein block.

The tail is where Curtis Everett (Chris Evans) lives, stewing and brewing waiting for a revolution that will re-distribute the train's vast resources. Serving as his mentor is triple amputee and sage Gilliam (genre legend John Hurt); while energetic teenager Edgar (Jamie Bell) plays sidekick. All past rebellions have failed and become dark history lessons, but Curtis believes he can make it to the front of the train. There he plans to confront the train's builder, Wilford (Ed Harris), who has become a god to many of the train's passengers. Among Wilford’s acolytes is Mason (Tilda Swinton), the Minister of the Train, who is dedicated to maintaining its cruel caste system.

This might seem like a lot of setup. The film's complex plot might be part of the reason that The Weinstein Company is entrusting Snowpiercer only to a limited release. However, Bong Joon-ho is a true storyteller, keeping his audience engaged and as informed as they need to be as Curtis's journey progresses, lush with tension. Thoughtfully unfolding the plot through character, the director binds us quickly to Curtis, whose eyes burn with determination. With a motley team made up of a drug-addled engineer (Song Kang-ho) and his junkie daughter (Ko Ah-Sung), a grieving mother (Octavia Spencer), and a silent warrior, Curtis forges his way from one compartment to the next. Each door unlocks a new element to this fascinating post-apocalyptic world, adding another rich layer to Snowpiercer's story.

To put it simply, I love this movie.

While adapted from a little-known graphic novel, it clearly pulls inspiration from the aesthetic styles of Terry Gilliam's dystopias (Gilliam himself gets a nod in the name of Hurt's character). Yet Snowpiercer feels exhilaratingly original. The faces are familiar. Yet caked in grime, robbed of limbs, and twisted in regret and pain, we see these actors in ways we haven’t before. Chris Evans is outstanding as Curtis, who is plagued by a haunting past he wears like a heavy cloak. Thanks to Evans’ screen presence, dark garbs and broad shoulders, we believe in his strength, and instantly understand why the others follow him. But in one climactic confession, you'll be left drop jawed, looking at Evans and thinking, "Captain America just said that!" It's shocking, yet sickeningly astonishing.

Playing the wizened warrior, John Hurt is expectedly wonderful, giving the film an instant gravitas and genre cred with his inclusion. Octavia Spencer gets little screentime, yet carves out a heartbreaking arc as a desperate mother looking for her lost little boy. Jamie Bell is scrappy and heart-warming as the overeager rebel Edgar. Ed Harris chills us as the practical but cold god Wilford. Alison Pill makes an appearance as a jolly and demented schoolteacher. And Song Kang-ho and Ko Ah-Sung, who memorably co-starred in Bong Joon-ho's biggest hit to date The Host, are tender and funny as the ever-high father and daughter. Kang-ho even gets moments of profound pathos, and through a futuristic translation device isn't handicapped by having to perform in English. Even amongst all these great performances, however, still the standout is Tilda Swinton.

I've written before how Swinton is having an amazing year, offering wildly different but fantastic portrayals in three unique films. But here, Swinton works magic. As Minister of The Train, she's the disciplinarian, forced to rule over the Tail with an iron fist. She is proud of her classist beliefs, firmly lecturing these have-nots on their "place" at the bottom of the ladder. Her speeches seem outlandish and absurd, but then you realize how they speak to a very real-world and troubling thought process. But as she wields lengthy, ideology-thick monologues, Swinton also does something wondrous. She makes us laugh. Her portrayal of this preposterous woman not only sets up the world and the film's critique of modern society, but also mocks Mason's views by her own ridiculousness. Of course, if you're not one for subtext, Swinton's sneering tyrant can be enjoyed purely for her over-the-top inhumanity and hilarious delivery.

All in all, Snowpiercer is extraordinary, and it's a crime that it's being lost in the shuffle amid bigger, showier summer blockbusters. Bong Joon-ho has manifested a textured and compelling world, filled with characters who demand our attention and empathy. Its production design is so detailed that the train itself should be counted as a character. You could easily get lost in the art design alone. This is a dark, but deeply beautiful movie, punctuated by edge-of-your-seat thrills and unexpected laughs. Admittedly, there are a few plot holes along the way, but by and large, Snowpiercer is riveting, hugely entertaining, and unforgettable. I fear it won't get the attention it deserves this summer. But if there's any justice in cinema, it will eventually be recognized as a sci-fi epic it is.