The third major theatrical Stephen King adaption by Frank Darabont (who did pretty well with Shawshank and Green Mile) doesn't take place in a prison, but it's still about a bunch of people who are trapped and any attempt to escape could be fatal!  A strange mist rolls into town, and lurking within it are all sorts of icky monsters!  Ordinary folks hiding in a supermarket can't deal with the horror (or each other) for very long and soon many of them are on their way to express check-out!  King's short story was really scary, despite its piss-poor ending.  Darabont fixes that here, and drops a whopper of a conclusion on us.  Any first-time viewers are in for a shock, so if you "mist" this movie, watch it now!  And by the way, it's not the same as The Fog.  That's harder to see through.  But awesome to watch!