Unstoppable is the second Tony Scott film in a row that's involved Denzel Washington and trains. While The Taking of Pelham 123 was an absolute mess that disgraced the original, Unstoppable is, well, just that. The movie barrels through it's just over hour and a half running time with very little plot and enough action to make this an incredibly entertaining film.
I'd try and expand on the plot, but it's incredibly simple: Out of control train barrels through Pennsylvania with incredibly toxic chemicals. A veteran engineer, played by Denzel, and the young new guy he's training, played by Chris Pine, are the only ones who can stop it. Yep, that's it.
There's not much room for character development, but really, there doesn't need to be. The whole point of a movie like this is to enjoy the ride. Scott keeps things moving with his patented TV commercial style. His love of the extreme closeup works well here, as it makes it even harder to see what's around the next corner. As long as you remember not to go into Unstoppable with anything but a need for a crazy train, you won't be disappointed.