In space, no one can hear you scream. In fact, no one can hear anything at all. But the sound of silence is a key reason why Gravity works. It's haunting. It's hopeful. It's an extraordinary experience, and easily one of the finest films of the year.

Directed by Alfonso Cuarón of Children of Men and Harry Potter and the Prisoner of Azkaban fame, Gravity boasts a simple premise: Medical engineer Ryan Stone (played by Oscar winner Sandra Bullock) must fight for her life when her first space shuttle mission goes horribly wrong. Satellite debris obliterates the space shuttle Explorer, leaving Stone with few options if she wants to stay alive. How strong is her desire to live? How far is she willing to push herself? How long can she combat seemingly insurmountable odds?

Those are the questions at the core of Gravity. It isn't a film built on wild twists; Dr. Stone wasn’t a ghost the whole time, and the space debris isn’t made of people (not all of it, anyway). Instead, Gravity finds its weight by keying in on a straightforward story extraordinarily rendered. Stone is a real person in real danger in absolutely unreal circumstances, beautifully realized by Cuarón and cinematographer Emmanuel Lubezki, among others.

As Stone, Bullock is our eyes and ears into the world of Gravity. Perhaps you'll tire of her grunts and groans, but it's more likely you'll find yourself breathless right along with her, once you realize the gravity (ahem) of her situation. Stone's exhaustion is immediate, and it doesn't take much imagination to understand why. Somehow, she manages to amp herself up as the tale moves along. It's an impressive performance that shows another side of Bullock's talents, imaginative in ways few other actors could have conveyed. Gravity almost starred the likes of Scarlett Johansson, Blake Lively and Natalie Portman in the Stone role. Having seen the film, it's virtually impossible to conceive of anyone other than Bullock leading the way.

Similarly, the film's co-lead, retiring astronaut Matt Kowalski, almost went to Robert Downey Jr.; he ultimately left due to scheduling conflicts, and the role went to the inimitable George Clooney. Again, it's difficult to picture Gravity with anyone else as Kowalski, even someone as talented as Downey. There are times where you can almost hear Kowalski's dialogue delivered with Downey's signature wit. But the warmth and gravitas in Clooney's performance is an essential part of what makes the film so great. He represents a soothing voice in all of the chaos, a pillar of centeredness, compassion and wonder as Stone and Kowalski's world falls apart all around them. Expect the Oscar winner to have at least one more Oscar nomination to his name by this time next year.

Bullock and Clooney are the human faces of Gravity, but the real show-stopper is the setting: the vast expanse of space, the dotting of stars in the deep black beyond, the ruinous rubble of space-shuttles and debris, the hulking terror of Stone's physical world coming undone … the loneliness, and the possibility, of space. The immensely cinematic Cuarón out-Cuaróns himself with unflinching and unbroken shots aplenty, shots that imbue the entire film with an authentic sense of place. On looks alone, Gravity is breathtaking in the truest sense of the word.

Also breathtaking: the sound of Gravity; specifically, the noiselessness of massive space-explosions, with Bullock's breathlessness and composer Steven Price's score left to fill the aural void. That score in particular deserves endless praise, harrowing at turns and empowering at others. You can listen to tracks from the Gravity score completely out of context and feel great pangs of sadness, tremors of terror, and unfailing hope, all with a few flicks of the "next" button. It's one of the great scores of the year.

James Cameron called Gravity "the best space film ever done," and he might not be wrong. The film is, in a word, fantastic. It starts big and only gets bigger, while still allowing its two leads to wear their hearts on their sleeves. The less said about the way the film and characters unfold, the better. Words don't do it justice. It's an experience that digs into the viewer's heart and never lets go.

Gravity opens Friday nationwide.