Square Enix wants you to know that Zack is one bad guy. Bad, of course, meaning good or cool. This CG video shows Zack dropping atop a train, immediately dodging bullets and generally causing chaos and mayhem. All in good fun, of course.
If the video streams a bit slowly for you, then hit pause once while its loading. Give it a few seconds of breathing room, and you should be set.
[Update: For more Crisis Core goodness, check out new screens at The Magic Box.]