Denzel Washington is to work with director Tony Scott for a fifth time on the action/thriller Unstoppable. The pair just recently finished shooting remake The Taking of Pelham 123, with John Travolta, so obviously like working together. This film is apparently loosely based on a true story of a runaway train that was packed to the brim with dangerous chemicals and the likes. Washington will play an old school engineer, who teams up with a newbie train driver to stop the aforementioned runaway train before the chemicals kill everyone. Sounds familiar, but with the calibre of director and star attached, there must've been something about the script (by Die Hard 4.0 writer Mark Bomback) that made them sign on.