The story is hard to explain without giving too much away. DiCaprio and company are a group of people who have crafted a way to dive into the dreams of people and inhabit their dream-worlds, inspiring the dreamer to create an alternate world, with alternate truths, all to gather information.
Nolan's screenplay is so involved, it seemed almost hard to follow at first, which I think was the point. About 20 minutes into the movie, I stopped trying to scientifically figure it out, and I just trusted the filmmaker. He does spend almost the first half explaining how it basically works. But, once he feels like you've gotten your fill, the action (and incredible special effects) do not stop. At one point you're literally watching four different action sequences playing out together. Incredible.
The special effects, alone, are worth seeing the film. Cities folding on top of each other. An entire fight scene in a zero gravity world. The scenes put the iconic Matrix fight scenes to shame.
The performances are top-notch. Cotillard is especially intriguing as DiCaprio's dead wife. She puts so much conviction in her performances, it's easy to understand why she's an Academy Award winner. It's not DiCaprio's best work ever, but it's still a worthy reason to watch. He never disappoints.
Being one of summer's, and the year's, most hyped about films, it definitely lives up to it's expectations. Christopher Nolan is quickly putting himself higher and higher on the list of great directors. Not quite a Spielberg or Scorcese, but he at least deserves to sit at the table next to their's.