No one can accuse Christopher Nolan of a lack of ambition. The man who turned a costumed superhero into an operatic crime trilogy and set a heist film inside a man’s dreams has made his career out of original ideas painted onto a giant canvas with the largest stakes possible. It was inevitable, then, that he would eventually turn his directorial gaze to the sky; the vast, unknowable expanse of space is just the sort of setting to cater to Nolan’s distinct proclivities. His new film Interstellar has done just that, unspooling a story of human survival that traverses the stars and stretches across galaxies. Nolan is not the sort of person to take the easy way out.

Working from a screenplay by Nolan and his frequent collaborator/brother Jonathan, Interstellar follows Cooper (Matthew McConaughey), a test pilot turned farmer doing his best to support his family while the Earth dies around him. A mysterious blight has claimed the lives of most of America’s crops save corn, and the midwest is under constant siege by dust storms. Space travel has been propagandized into the dirt in a vain attempt to focus on immediate survival over the future viability of the human race. Gravitational disturbances lead Cooper to accidentally stumble upon NORAD and the remnants of NASA, only to find his college teacher, Professor Brand (Michael Caine) and his daughter Amelia (Anne Hathaway) racing against time to find habitable planets on the other end of a wormhole that was discovered by Saturn. Against the wishes of his daughter Murph (Mackenzie Foy) and his father (John Lithgow), Cooper is drafted into piloting a last ditch effort into another galaxy to try and find a new home for himself, his family and the entire human race.

Clearly, Nolan has not taken his foot off the gas in his ninth feature, but he does take his time reaching full throttle. The first act of Interstellar is entirely Earthbound, putting the focus squarely on Cooper and his family, specifically his daughter. This part of the film is quaint, though it does feature quite a bit of exposition. Nolan’s scripts have always been big on talking through every aspect of his world, its plot and its themes, and he wastes no time doing the same here. Still, the dying world is engaging, and the visuals are lush and satisfying. Even without frequent collaborator Wally Pfister behind the camera (he was too busy directing Transcendence), the camera eye remains strong, and Hoyte Van Hoytema has picked up right where Pfister left off. This is especially true once the setting turns cosmic, with the vast expanse of space and the harsh vistas of alien worlds given a wonderful widescreen treatment. The exposition never stops though, and as the plot spins ever further outward into discussions of the fifth dimension and quantum gravity and time relativity, it takes quite a few speeches to keep up with it all. Over the course of nearly three hours, it can be an exhausting experience.

This is not to say the story is bad; it is perfectly fine in its own sort of science fiction-y way. There is no need to bother with the specifics of it all; it barrels ahead into mind bending space by the end of the second act and does so with enough gusto that it does not really matter if it all makes sense or not. This is often the case with science fiction films that feature PhDs in astrophysics discussing the finer points of space travel and quantum mechanics. They make sense to a point and do not make all that much sense after that point, but under the correct hands they are comprehensible enough to go along for the ride. The efficacy of the plot is secondary to the 2001’s and Gravitys and Prometheuses and Interstellars of the world. What matters is what surrounds it: the mood, the tone, the emotional resonance. Those building blocks are vital to the connective tissue of science fiction that allows it to be the allegory it so often is for its audience.

It is in this connective tissue, unfortunately, that Interstellar is at its weakest. It wears its exposition on its sleeve, but it is also far too concerned with distilling its emotional themes into the simplest and most cliched platitudes possible and spelling that out through the mouths of its stars. It is this dialogue, this reliance on hitting its themes over and over again as hard as possible, that makes its 169 minutes feel like four and a half hours. The pacing of the second act is glacial, and there are plenty of digressions that go nowhere and offer nothing beyond additional minutes in the theater. By the time the craziness kicks in, any emotional connection to the material and its characters is gone. This is a film that wants to have the sort of detached, clinical quality of 2001: A Space Odyssey (and Kubrick’s fingerprints are all over this, even down to the space docking scenes and robots that look like walking monoliths) while retaining the humanity of more personal works, and Nolan just cannot pull off both, serving to offer two diluted halves instead of a satisfying whole. Hathaway gets the worst of it, trying her best to make the garbage spilling out of her mouth into something worthwhile, but the game is over before she even gets there.

Interstellar’s technical merits are its saving grace. The use of sound is top notch, and Hans Zimmer’s score is noticeably less bombastic than his other recent collaborations with Nolan. It does not drown itself in action set pieces, and when it does go for moments of high tension (there is a particularly spectacular docking sequence late in the film that brings the goods), it is breathtaking. Indeed, it finds quite a bit of common ground with last year’s space blockbuster Gravity, another film of astounding technical virtuosity and a titanically dull script. Interstellar is overstuffed where Gravity was underdrawn, but both suffer from bouts of truly horrid dialogue that undermine its characters and their feelings. To watch Interstellar is a marvellous experience, but to listen to it is entirely unfulfilling. Nolan reaches for the heights of the best science fiction has to offer, but his ship comes up short, and can do nothing but burn up on reentry. At least the crash is beautiful.