A Manhattan bicycle messenger (Joseph Gordon-Levitt) picks up a package containing what Hitchcock used to call the MacGuffin (something the villains are after–it doesn’t matter what) and spends the rest of the movie fleeing a dirty cop who wants it back (Michael Shannon). This thriller by David Koepp functions as one long chase scene, halting occasionally for flashbacks that explain why the cop wants the package. (Hey, didn’t we just decide it doesn’t matter?) The cycling action is fun, and there’s a lot of pop mythology about the tao of bike messengers, though the latter sounds as if it were written by someone who pays for rush service, not someone who provides it.