If a train leaves southern Pennsylvania at 9 a.m. going about 60 mph, and another train—engineered by Denzel Washington and Chris Pine—leaves central Pennsylvania at 11 a.m., going in reverse, which one will arrive at the end of the movie first? If that film is Unstoppable, the answer is hardly worth thinking about, both because you probably already know the answer, and because it’s actually more fun to just let seasoned action director Tony Scott open his toolbox and see what works. Surprisingly, most of the film does work. Unstoppable isn’t just about a runaway train hurtling toward certain disaster; more than anything, it’s about how to make a stripped-down, entertaining seat-filler about a runaway train hurtling toward certain disaster.